Welcome to the world of CD-R software conflict - and ROXIO does tend to be a "bad neighbour" to other programs, though prassi-engined programs (of which I believe Sonic is one) also have issues with Nero 6 (or is that the other way round?). WinME is also not a well-liked platform for CD-R ... it tended to have far more problems than 98SE.
Which versions? - and what came with the drive... I thought Liteon always bundled Nero?