PHP not working on virtual servers

I have a fresh install going on Ubuntu everything checks out ok but PHP4 and 5 are not working for virtual hosts, main site is fine.

I installed php5-mysql by hand as it was missing in the installed applications and it works fine for the main site but not for any virtual site.

For virtual sites if I drop infophp.php file in the public www folder I get the catch all "Internal Server Error" from Apache.

Any thoughts?

Thanks in advance.