PC does not see dvd drive

Please Help - For some reason when my wife or son are logged into their windows user accounts on my WinXp machine, and I log in with out logging them off, my PC will not recognize the DVD burner.

If I go into their account and log them off, it works fine as far as reading a cd or dvd (movie or game) but it will not work for burning a disk. If I put a blank DVD or CD in the drive, and click on the dvd drive in explorer, it tells me:
“g:\ is inaccessible - Incorrect Function”.

I had this same problem with my Pioneer 20x DVD burner, and went through the process of updating the firm ware and then being told that the Pioneer has problems with my MoBo’s chipset.

I sold it on Ebay and bought this one just to go through the same problems.

Here are my PC Specs:
nVidia 680i SLI MoBo
Intel Core2 Quad q6600 @ 2.40 Ghz
LiteOn LH-20A1L SATA DVD Burner
nVidia Geforce 8800 GTS 512Mb Video
Sound Blaster X-Fi Audio
2Gb Corsair DDR2 Memory

Any Help will be very much appreciated…