I had this happening and kept on happening over a few different flashes of MightyROM and Juicy. [I was so convinced that it wasn't my phone that was causing it that my wife and I both called Sprint a few times to have them troubleshoot the network!]
After a few inquiries, Mike suggested doing a hard reset using the 1234 Clear Storage method instead of just flashing or using the buttons. I did it twice, just to make sure. Not one problem since then.
