You might have read the comments about the Facebook 3.2 and Facebook 3.2.1 posts and is also possible that you might had seen that the latest version(s) of the uber-popular social networking app is having a little trouble on Jailbroken iPhones. It seems like Facebook is aware of the problems and working on a fix:
When you jailbroken your device, you may have experienced problems with the latest updates. The problem has been identified and the issue now have an update with a fix coming soon.
BiteSMS for Jailbreak is often mentioned as a source of clash until the fix is pushed out and you can uninstall it to get Facebook working or just use touch.facebook.com to get your social on.
[Facebook, thanks Robert!]