My Windows 7 computer can "see" the board, (as COM 31) and I have loaded the VCP driver. The GUI says that I'm connected, but it doesn't update or let me do anything. I have tried several revisions of GUI. When I try to use AVRDUDE to program the board, I get errors. (unfortunately, I can't remember what they were) and when I try to flash new software using Arduino, I get

avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x00

The board USED to have a RED LED flashing continuously, now the RED LED flashes only briefly when I connect the USB port.

What might be wrong?