03-22-2010 08:18 PM
Hi and Welcome to the Forums!
Anytime random strange behavior or sluggishness creeps in, the first thing to do is a battery pop reboot. With power ON, remove the back cover and pull out the battery. Wait about a minute then replace the battery and cover. Power up and wait patiently through the long reboot -- ~5 minutes. See if things have returned to good operation. Like all computing devices, BB's suffer from memory leaks and such...with a hard reboot being the best cure.
03-22-2010 09:48 PM
Did it ever work OK? If so, what changed just before it stopped working? A new Theme? Some new app? Some update? The tiniest thing could be causal.
If nothing above applies, then the diagnostic activity is tedious...reinstalling your OS from scratch and adding nothing. Then adding things one at a time very slowly until the behavior returns...indicating the culprit.
Given how new your BB is, if nothing above applies, then I do advise taking it back in...there's no need to struggle with this type of thing with a brand new device.