iPhone repair needed error message

I first got one of these on Sunday evening and followed the steps in http://support.apple.com/kb/TS1683 as stated. Everything was fine but called apple since I was worried I am a developer and loaded the 2.1 beta firmware for work to test a few things and then reverted back to 2.0. Now this afternoon I got it again and reset the phone and its fine again but for how long. Anyone seen this before and know maybe what could be the problem?