I understand about sprite backup. There are two issues with it. First, check and maybe update the sprite version when moving from a WM version such as 6.0 to 6.1. Plus what you said, don't try to restore a backup from a previous version to a new one. Currently, Sprite works between 6.0 and 6.1 bit needed a new version between 5.0 and 6.0. I'm not sure about using it on 6.5 or other roms.
I was amazed at how many of my apps failed on htc TP2 that worked fine on the XV6800. It had to do with the apps adaptability to the new screen size or ones that expected to have particular hard buttons that are missing on the TP2.