can you elaborate more? does it freeze as soon as you open the app?
the Facebook app is very poorly programmed. It slows down the phone like no other, in all honesty I would recommend using the mobile site over the Facebook app.
It is entirely possible that what you are experiencing is just the app being Sllllooooowwwww. Try waiting a few minutes or so and see if everything starts to work correctly.
mine was really slow too. i did a wipe and reinstalled .732 and reloaded my apps. everything has worked fine since. i think the upgrade without a wipe is what started my problem.