Help 105 not reading dvd

I just installed my pioneer 105 on my win xp/sp1 system and it was detected and the drivers were installed. Before trying it out, I upgraded the firmware to 1.30. When I put in any kind of dvd it tries to read (spins) for about 1 minute then quits trying. The 105 can read cds fine and I have a dvd-rom drive that works fine. Any suggestions would be appreciated, especially on how to unflash back to an older firmware. Thanks.