NEC 3550A doesnt read dvds!

hi. i perchased NEC 3550A dvd witer few days ago and my problem began! the drive doesnt recognize 90% of dvds. it is ok with cd and audio ones. when i insert a dvd my power dvd.6 says “there is no disk in the drive!”( or sth like that!) when i go to the drive it seems like a blank dvd.i updated the firmware, motherboard bios, VGA adaptor. i have changed my IDE cabel and now it is 80 pin. there is no difference between primary slave, sec. master or sec. slave. i have tried all ! my OS is now XP SP2. the DMA is also active and the hardware acceleration is on. finally i tried the damn dvd drive on another PC and it worked very good !! even very scratchy and damaged dvd, played without problem. plz help me! can it be an incompatibility issue?? if so, what can i do?I have nothing more to do !!!

ps: the mother board is soltek sl-85dr3-c . cpu 2.4 intel full, if it is the matter of concern.

Welcome to the forum.
Some things you may try. Remove the IDE drivers if they are the ones supplied with your motherboard (including updates) and replace them with the standard MS IDE drivers.

Remove any packet writing software like InCD.
Also some applications like Alcohol can cause problems.