Blank Pages after upgrade of MySQL and PHP

I'm running my forums on vBulletin 3.7.0 and using vBSEO 3.1.0 and just tonight upgraded my server from MySQL 4.1.20 to MySQL 5.0.58 and also updated my PHP version from 4.3.9 to 5.1.6. After restarting the httpd server (Apache 2.0.59) I'm having problems with all rewritten URL's .html files not showing at all.

Example:

testing - NECO Forums

comes up with a blank page

HOWEVER,

Forum Issues - NECO Forums

page renders, but all linked pages (rewritten with vBSEO), are not rendered.

Do I have to change anything in the config since I have updated PHP and MySQL? I didn't change anything file wise, I simply upgraded the servers.

testing - NECO Forums loads fine for me.

Are you seeing any errors in the error log?

What's your memory limit set to?

Memory limit for which server?

I have the following line in my httpd logs:

Failed loading /usr/lib/php4/php_ioncube_loader_lin_4.3.so: /usr/lib/php4/php_ioncube_loader_lin_4.3.so: undefined symbol: zend_hash_add_or_update

I have searched through my httpd.conf file and can't find any reference to this module.

Grab it from PHP Encoder, protection, installer and performance tools from ionCube: Home

It's so big that it's not included in the vbseo distro.

I tracked down the reference to this .so and fixed it. However, the problem is still occuring.

Turning vBSEO on/off doesn't seem to make a difference ... I'm not sure if this is a vBSEO problem or not. However, after experiencing this and searching around, many people have experienced the blank page problem when using vBSEO.

It turned out to be the memory_limit setting in the php.ini file ... thanks for pointing me in the right direction!!!!

No worries!

Meh ... I got to upgrade from 3.1.0 to 3.2.0 RC5 as a result, so it's all good!