HTC Droid Eris :: Randpm Things Happening With Droid Eris

i have a droid eris and it does random things. For instance when exiting the browser it goes from home all the way to the left and when i go to slide it back to home it stops and slides it all the way back to the left. It will randomly call people, freeze up, hang up on calls, shut off while in a call, and change pages while on the browser, freezes up in a call so you cant go to different things while talking. Ive done a hard reset 3 times and and soft reset many of times. I dont want to do a master reset and lose everything. Is that my only option if so is there a way to backup the files and contacts on my pc. I have taken it into verizon many of times and all they say is to reset it and nothing else.