iTunes 7.7 question

Recently, I upgraded my iTunes to 7.7, After restarting the Mac, I clicked on iTunes but it responded that the iTunes library was another version and it couldn't open it. I went back to the 7.6 one and it worked fine. Anyone else have this issue?

I haven't run the update yet, but itunes does back-up the library to an XML file that you can import

I will see if I get any issues with the update, I have done a recent back-up so I will be ok