Stomp RNM 4.5 not finding drive even after pxdrv.dll update

I have been using this program with the updated pxdrv.dll with no problems until it suddenly says it can’t find a drive (other burning software can find the drive) I have tried all three pxdrv.dll’s from http://club.cdfreaks.com/showthread.php?t=102905
as I have a NEC 3500AG. I have tried them with and without updating the engine to 507 first.
The pxdrv.dll update has always worked before, I cannot figure out why not now. I really like this app so if anyone can help I would be most grateful.