Problem:
My DVD writer suddenly went very slow and it took almost 90 minutes to burn the data DVD. The problem was quite easy to solve once you check the DVD drive transfer mode. Booth Hard Drive and DVD Drive should be in the DMA mode. If DVD have some reading/writing errors windows will switch DVD to slow PIO transfer mode.

Solution:
To solve the problem you need to change transfer mode (Control Panel >> System >> Hardware >> Device Manager IDE ATA/ATAPI controllers >> Primary or Secondary IDE Channel) back to DMA and reboot system. If this do not help or if your drive is still in PIO mode simply uninstall the channel and reboot. New hardware will be detected at system booting.

Any comments welcome.