Help, BB turning itself off for no reason

I have had my BB (AT&T pink pearl 8110) since this past Christmas, and every so often it will just shut off for no reason. I only have a few apps, delete my e-mails and sms frequently and keep and eye on available memory. I do battery pulls every few days. I do not have it set up to turn itself on and off, and I never let the battery get below half way. So I am pretty sure it is not a battery issue or a low memory issue. AT&T is willing to send me a replacement but if I can fix this one I would rather do that than take my chances on a refurb. My husband was suggesting doing a wipe and then reinstalling the os... Can anyone walk me through that or send me in the right direction? Thanks in advance :)

I would take the refurb, you never know if this thing can happen later on if it gets fixed by a wipe, i would back up all the data on the computer through the bb desktop manager and when you get the new one just restore the back up file