problem updating to 2.0.24

[marceff]

just updated from 2.0.22, now it doesn't go to products or any other VM2 pages, sometimes giving http 500 error.
My server info: joomla 2.5.11
Linux orion2 3.2.0-30-generic #48-Ubuntu SMP Fri Aug 24 16:52:48 UTC 2012 x86_64
5.3.10-1ubuntu3.3+hs.1
Apache
please help me to solve the problem or how to downgrade back to 2.0.22 (no backup as site is not done yet).

thanks

[jenkinhill]

First update Joomla: http://forum.virtuemart.net/index.php?topic=118683.0

Then this may help http://forum.virtuemart.net/index.php?topic=118946.msg404053#msg404053

Then start making backups!

[marceff]

Thanks for you suggestions. I did updated from j2.511 to j2.5.14 and I checked that "use joomla default" was selected but did not help.
I am using two Gantry templates, one for home and one for e-commerce pages. So home is ok, but it doesn't show other VM pages as products, basket, ecc. It does show Joomla pages. Any further suggestion?

I sure got your "backup" message! I made a very big mistake 

[marceff]

It seems to be ok now... dont't know really how, if not for Jenkinhill suggestions. I think that joomla update did work. At the beginning nothing changed, then, after I re-saved some categories and products, everything came right.
Thank you for the help.