3.1.1→3.1.2に更新したら、サーバーエラーでページが表示できなくなりまし

[mongstyle]

バージョンを3.1.1→3.1.2　自動更新しました。
更新完了まで行きましたが、500　Internal Server Error　となり、以下が表示され、正常にページが表示されなくなりました。
・・・・・・・・・・・・・・・
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator to inform of the time the error occurred and of anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
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【サーバー：ロケットネット　の　エラーログ　には（更新後の）】
[Thu May 19 16:30:54 2011] [error] [client 113.124.4.58] Premature end of script headers: index.php, referer: http://●●●.com/wp-admin/update-core.php?action=do-core-upgrade
[Thu May 19 16:31:05 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:31:05 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 24 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 172
[Thu May 19 16:31:05 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 77 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/plugin.php on line 134
[Thu May 19 16:31:17 2011] [error] [client 113.124.4.58] Premature end of script headers: index.php, referer: http://●●●.com/wp-admin/update-core.php?action=do-core-upgrade
[Thu May 19 16:32:11 2011] [error] [client 113.124.4.58] Premature end of script headers: edit.php, referer: http://●●●.com/wp-admin/update-core.php?action=do-core-upgrade
[Thu May 19 16:32:12 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:33:01 2011] [error] [client 67.18.5.138] Premature end of script headers: index.php
[Thu May 19 16:37:02 2011] [error] [client 113.124.4.58] Premature end of script headers: plugins.php, referer: http://●●●.com/wp-admin/update-core.php?action=do-core-upgrade
[Thu May 19 16:37:03 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:39:55 2011] [error] [client 113.124.4.58] Premature end of script headers: index.php, referer: http://●●●.com/wp-admin/update-core.php?action=do-core-upgrade
[Thu May 19 16:39:56 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:40:00 2011] [error] [client 113.124.4.58] Premature end of script headers: index.php, referer: http://●●●.com/wp-admin/update-core.php?action=do-core-upgrade
[Thu May 19 16:40:05 2011] [error] [client 113.124.4.58] Premature end of script headers: index.php, referer: http://●●●.com/wp-admin/update-core.php?action=do-core-upgrade
[Thu May 19 16:45:41 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 78 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 204
[Thu May 19 16:45:41 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:46:45 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 77 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 204
[Thu May 19 16:46:46 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:49:08 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:49:08 2011] [error] [client 113.124.4.58] Premature end of script headers: plugins.php, referer: http://●●●.com/wp-admin/post-new.php
[Thu May 19 16:49:47 2011] [error] [client 113.124.4.58] Premature end of script headers: options-general.php, referer: http://●●●.com/wp-admin/post-new.php
[Thu May 19 16:50:54 2011] [error] [client 113.124.4.58] Premature end of script headers: admin-ajax.php, referer: http://●●●.com/wp-admin/post-new.php
[Thu May 19 16:50:55 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:51:52 2011] [error] [client 113.124.4.58] Premature end of script headers: admin-ajax.php, referer: http://●●●.com/wp-admin/post-new.php
[Thu May 19 16:52:54 2011] [error] [client 113.124.4.58] Premature end of script headers: admin-ajax.php, referer: http://●●●.com/wp-admin/post-new.php
[Thu May 19 16:52:55 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:53:52 2011] [error] [client 113.124.4.58] Premature end of script headers: admin-ajax.php, referer: http://●●●.com/wp-admin/post-new.php
[Thu May 19 16:54:54 2011] [error] [client 113.124.4.58] Premature end of script headers: admin-ajax.php, referer: http://●●●.com/wp-admin/post-new.php
[Thu May 19 16:54:56 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:55:26 2011] [error] [client 113.124.4.58] Premature end of script headers: update-core.php, referer: http://●●●.com/wp-admin/post-new.php
[Thu May 19 16:55:51 2011] [error] [client 113.124.4.58] Premature end of script headers: index.php, referer: http://●●●.com/wp-admin/post-new.php
[Thu May 19 16:57:17 2011] [error] [client 113.124.4.58] Premature end of script headers: index.php, referer: http://●●●.com/wp-admin/post-new.php
[Thu May 19 16:57:18 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 16:57:22 2011] [error] [client 113.124.4.58] Premature end of script headers: index.php, referer: http://mong-style.com/wp-admin/post-new.php
[Thu May 19 16:57:31 2011] [error] [client 113.124.4.58] Premature end of script headers: index.php
[Thu May 19 16:58:02 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 199 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 17:17:48 2011] [error] [client 208.115.111.75] Premature end of script headers: index.php
[Thu May 19 17:17:49 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 17:22:48 2011] [error] [client 113.124.4.58] Premature end of script headers: index.php
[Thu May 19 17:22:49 2011] [warn] mod_fcgid: stderr: PHP Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 698 bytes) in /var/www/vhosts/●●●.com/httpdocs/wp-includes/pomo/mo.php on line 187
[Thu May 19 17:23:07 2011] [error] [client 66.249.68.102] Premature end of script headers: index.php

がありますが、何をどう対処したらいいのかが全くわかりません。

誠に恐縮ですが、対処方法をご教示頂ければ幸いです。
何卒よろしくお願い申し上げます。

・・・・・・・・・・・・・
サーバー環境
OS CentOS 5系
ウェブサーバー Apache 2.2
PHP 5.1.6
Perl 5.8.8
Apache-ASP 2.59
Python 2.4.3
Ruby 1.8.5
データベース MySQL 5.0.77
DNSサーバ BIND 9.3.6
・・・・・・・・・・・・・・・

です。
（素人につき、申し訳ございません。）

[aimaim]

ども。

PHP Fatal error: Allowed memory size of 33554432 bytes…

ってことは、PHPが使えるメモリーサイズ（おそらく32MB）の上限を超えちゃって
動作できないよってことです。
phpにもっと大きなメモリーサイズを割り当てる必要があります。

とりあえず、手軽な方から順に、以下の順に試してみてください。

対策１）wp-config.phpファイルに、次の1行を加えてみる。
define('WP_MEMORY_LIMIT', '64M');

対策２）もし、PHP.iniを直接編集できるなら、メモリー限度を32Mから64Mに引き上げてみる。（レンタルサーバでは、PHP.iniの編集を認めていないことが多いです。）
memory_limit = 64M

対策３）直接PHP.iniファイルを編集できないなら、試しに.htaccessファイルに次の１行を追加してみる。（レンタルサーバによっては、.htaccessでの設定変更ができないこともあります。）
php_value memory_limit 64M

対策４）レンタルサーバの管理者に相談してみて下さい。

[mongstyle]

aimaimさま

助かりました！

ご丁寧にわかりやすく説明して頂きましてありがとうございます。

対策1　にて　あっさり解決致しました。

本当にありがとうございました。

・・・・・・・・・・・・・・・・
素人なのですが、
現在　さくらインターネット・xserver・ロケットネット　の3つのサーバーでwordpressを利用しておりますが、

wordpressやプラグインのアップデートで
一番問題が少ないのが　さくら（ほとんどありませんでした。）
xserverは時々。
ロケットネットは頻繁です。

余談を書いてしまいましたが、初心者の方の参考になればと。

aimaimさま　この度は本当にありがとうございました！