Strange (PHP?) error after fresh 2.9.0 ubuntu server install

Hi everyone,
I hope someone can help with my baffling situation. I’ve googled and read tons of posts but I’m no closer to solving this.
I just installed ubuntu natty (11.04) server with asterisk 1.8.9.2 and freepbx 2.9.0 (from sources) on an OpenVZ VPS.
Ok, so I managed to compile and build everything according to instructions but now I have a strange problem which I cannot resolve.
Basically, when I log into the web interface after the install, I can see the index page alright and I can even open the FOP page. However, when I click on admin or on ARI, I get this strange behavior which I cannot debug.
What happens is that the pages (admin and ARI)load completely blank (even checking the html source it truly is blank). I’ve triple checked the directories and all the files are there where they should be (config.php, etc, etc) and I’ve checked the apache logs and there are no errors there. Now the weird thing is that once or twice I got a 500 internal server error message, but i cannot reproduce it anymore (page is blank and url is correct (ie config.php) but nothing happens - just blank page loaded but no error messages).
So I figured there must be some PHP error happening and I enabled error logging in php.ini, but nothing shows up there or in syslog.

Anyway, I’ve spent all day trying to hunt down this bug and I’m just about ready to give up and install asterisk and pbx again from scratch.

Anyone have any idea what the problem maybe (I tried firefox and chromium and both produce the blank page but no error messages).

Thanks