I suggest trying it in another PC if it still plays up return the drive and get it replaced after reflashing with the latest Sony fw or orig firmware if you have it.
There is always going to be that odd faulty drive so if you swap it for another LITE-ON, Pioneer or NEC you may get another faulty one but the chances are slim.
You could just get it replaced because it only a couple of weeks old (after flashing it back to standard fw) or get it replaced with one of the other 2 drives I mentioned.
I have a Pioneer 108 and it works just fine with good quality +/- R media, but you don't have the utils or support (from forums) that the Lite-On drives have, so far I haven't needed any modds for that drive.
My Lite-On 812S loves RICOHJPNR02 media so that is all I feed it and I have no problems doing that.
It is a bit of a gamble on which drive to purchase there seems to be just as many faults per quanity sold with each brand. Lite-Ons as a rule prefer +R media to -R so if you are using -R media I would suggest a different brand drive than a Lite-On.