Atomicorp

Hi All.
Since I had to migrate to a new server with the new Plesk 10.2 (I miss my old plesk 8.0.1 that works smothly), I'm having issues with some PHP scripts, but I no have idea how to address some of them.
I have a domain with joomla (1.5.20 Stable) that was working fine at the old server. At the new server I only get Error 500.
I didn't see any information at error_log or access_log, no idea where to put my eye. I removed .htaccess file, I checked owner:group. All looks normal bur the error stills.
If I install joomla (same version) from the applications in plesk it works.

Where I can search to find the problem? Witch log?

Tnx in advantage

Edit to add some data:
Linux host 2.6.18-238.9.1.el5 #1 SMP Tue Apr 12 18:10:13 EDT 2011 x86_64
MySQL 5.1.56
PHP 5.3.6
Web Server: Apache
Web Server to PHP interface: apache2handler
Zend Engine v2.3.0, Copyright (c) 1998-2011 Zend Technologies
with eAccelerator v0.9.6-svn358-dev, Copyright (c) 2004-2007 eAccelerator, by eAccelerator
with the ionCube PHP Loader v4.0.5, Copyright (c) 2002-2011, by ionCube Ltd.
with Suhosin v0.9.32.1, Copyright (c) 2007-2010, by SektionEins GmbH

Check fastcgi, I know PSA had some issues with certain versions of fastcgi.

The test page for fastcgi shows normal.
Anyway finally I solved deleting all and uploading again. The problem is I don't know why it was failing

Tnx mikeshinn