Iphone 3g repeatedly Locks itself

[Dynamixx]

My iphone will at random enter into a fit and start locking itself every 2 or 3 seconds. Sometimes it will wait 10 seconds.. some times it will lock 2-3 times within 5 seconds. Also at times it will bring up the "power-off" slider. Its Like someone is just constantly pressing the lock button at random times. I've gone into settings and turned Auto-lock to never, but that doesnt help. i've never dropped the phone (its only 2 weeks old) so the button isn't damaged or pushed in.

What i got out of tech support is that it is a software problem and they are willing to send me a new one.. too bad i bought it off craigs list and if i sent mine in.. they'd send the new one to the original owner.

I've done a full restore 3 times. I tried it twice, but then I'd always restore from back up after doing a fresh restore and jailbreak.. So the third time around i decided to set it up as a brand new iphone but the same problem appeared after 3-4 hours of use.

One last question... Is it possible to using a program like Iphone Browser for windows, erase ever single file, and then restore the iphone?? A part of me thinks that there are some third party files sitting on my iphone that aren't getting erased by the conventional restore. And if i can some how just wipe the entire Iphone clean and then restore, then I have a hunch that it might solve the problem.

Anyways, Thanks for your Help.

Some info:

Iphone 3g
2.1 Firmware
Jailbroken
Windows XP

[ALL DAY]

^If they're willing to send you a new one, I'm sure you can take it to the Apple store and they'll switch it out for you...

Sounds quite annoying though, almost like a hardware problem, but if they said it was software, I guess they'd know better than I.