Keyboard and button response problems can be cause by moisture exposure. It may be coincidence that you noticed this at the same time as the OS upgrade.
Be aware that a sweaty pocket, foggy shower room, etc have been reported to cause problems.
If this is a possibility in your case, you need to remove the battery now, and let the device dry. See the article at http://blackberryfaq.com/index.php/G...ckBerry_Wet%3F