I put a liteon in a client's computer (which was a AMD something 166mhz processor w/32 megs of ram and 2 gig hard drive) and it worked fine right from the beginning.
I also have a 24x liteon and I have had harly any problems with mine, other than it's a little picky about the media. Otherwise I can't really complain. Obviously if the computer can't even recognize a burner I'd say you've got a real crappy mobo or something like that.
I'm sick of hearing buy plextor. It's just like buy IBM, and look what happened. (well only the fact that plextors do work I guess you can't compare them)