I also had issues with it earlier on in the year. Took forever to move between pages...and a few other things. I also had something serious draining my battery. No loss of data or airtime though. I went over the top and wiped the phone completely, hooked it up to PC and installed new kernel, Cyanogenmod and the Google Apps and restored my backups. Phone is like new. But that's just me
As Chrisc said, maybe uninstall, clear the cache and d/load from the app store again.
Sent from my telephone.