I have a rewriter YAMAHA CRW2100E. The original firmware was 1.0g. I updated the firmware to version 1.0n (downloaded from YAMAHA official page), but now it does not work with the checkbox DMA set. When I want to burn a CD (simulation or real), it shows the message "Bad medium". When the checkbox is disabled, the rewriter works properly. Before I updated the firmware, it works with DMA activated or disabled. I have updated to version 1.0g again, but it works badly. Anybody can help me? Thank you.