Any specific error codes?
I would guess that this is almost certainly a media compatability problem. So you could try another brand. Having said that it may be worth checking with ULead that your DVD burner is supported.
COMPAQ something or other with 500Gb Boot Disk, 1Tb external Firewire Disk, 4Gb Memory and a super duper sound card, 19" TFT Monitor etc etc etc
Sony TRV33e : Sony TRV310e : Canon XM2
Sony Vegas Studio editions to v11
Remember, there is always more to learn than there is to teach.