As of late my pearl is generally running slower, chewing through the battery and slow to restart sometimes getting the 523 error. Seemed to start after a Facebook application upgrade. Facebook has been completely (I think) eradicated from the phone but performance hasn't improved.
Sometimes even though you've deleted an app, traces stay behind, just like on your PC. Might be time to do a backup, and wipe it clean. Facebook is a scourge on BlackBerries.
As Wulf stated, FaceBook is murder on the early BlackBerry devices. It has caused many major and minor malfinctions. They just don't have the memory necessary to support that app very long.
Posted from my CrackBerry at wapforums.crackberry.com