Welcome to the forums.
I see that you clear your memory a lot. I don't see you mentioning pulling the battery. Have you tried pulling the battery out of the device for 30 seconds (while the device is powered on)?
If that doesn't clear up your issue, you may try to upgrade your OS. 4.5 is available for your device. Not released yet from Verizon, but there is an officially released version from another carrier. It is a sticky thread in the 8300 Discussion Forum.