Verizon G'zOne - Technical Issue

Hello,
I recently purchased a G'zOne and it was working fine. Recently though, it has been randomly rebooting and if I answer a call or reply to a txt it will sometime shutoff. I took it to a Verizon store and ask them to take a look. They upgraded the firmware but that was about it. It was working fine for about 2 hours then started again. Any thoughts? Note - I haven't thrown it or held it under water...its been treated as a normal phone.
Thanks!

have you downloaded any software or put anything on the phone? ringtones or anything? I would think a software upgrade would do the trick.

Thanks for the reply...I had them to a software upgrade and it worked for about 2 hours, then started rebooting again. Got a new phone.