I also built myself a new PC recently and discovered a problem similar to the one pcxajb describes in the first message. My Samsung's SH-S183A DVD-drive performs terribly slow under Windows Vista. When I insert a CD-ROM or DVD-ROM into the drive, it takes a long time for the system to play the disk, if it plays at all. If the autorun works, it takes usually 5-10 minutes for it to do anything. If I try using Windows Eplorer to see the contents of the disc, the process is equally slow.
My motherboard is also Asus P5N32-E SLI, as mentioned in the first post, but my processor is E6420 and I'm running Vista instead of XP.
I would have thought this is a hardware problem, but I have a dual boot PC with both Vista and Ubuntu 7.04 in it and the SH-S183A works like a charm under Ubuntu... I also installed both the Vista and Ubuntu using the S183A-drive, and there was no problem whatsoever at the time. I guess it's safe to say, that in one way or another it is Windows-related problem, but that's where my skills end. Any help and suggestions are highly appreciated!