Sorry Igor I assumed you wouldn't want lots of threads covering the same issue. So I searched for the problem first and came accross this thread and thought it best to post here as it was marked as solved perhaps prematurely. Mind you I have noticed looking through these forums that many other paying members are reprimanded by mods about where they post so I guess I'm not alone.
Incidentally I have managed to solve my problem after reading peter's suggestion about the change to php.ini file. The htaccess option was giving an internal server error and the index.php option didn't work for me either. I didn't have access to the php.ini file as i am on shared hosting.
So I simply created a php.ini file with just the one line of code that Peter posted and saved it in the joomla root folder. Hopefully that will help others who will undoubtedly have the same problem.
Thanks for the post. This was the solution when I updated Gantry to 4.1.32 on a Joomla 2.5 site and received the same error. The site was using Cerulean template.