server php upgrade from 5.2 to 5.3 broke site

[jamesthedisciple]

Hi,
My hosting server (Lunarpages) php was upgraded from 5.2 to 5.3 and I was unable to login to any of my sites! Even with the special wordpress script to change the admin password.

I logged a ticket and their reply was some of my plugins and /or themes require php 5.2 and wont work with 5.3, and they set my shared host to php 5.2 and now I can login (to one at least).

Two of my sites only have Genesis 1.8.2 (backcountry theme) only, no plugins. Could this be a Genesis issue (unlikely, but I need to ask) or a setting on the server? If a setting, any ideas to get this going with php 5.3 or should I move host (which I am considering)?

Thanks
James