Yeah well depending on your integration type and what issues you have you can post but for instance like in the release notes if you use a standalone photopost style you can not use old styles you must delete your stylesheets directory and use the new stylesheets. If your using a forum integration and using some old style there can be issues with style mapping to older code so it all depends.
An answer all depends on your issue. I was sure when reading your php version you had to be getting deprecated errors since that old code was not designed to run on PHP 5