For some reason, my DVD Architect that came with Vegas 5 does not recognize my DVD writer. I bought Ulead DVD workshop to check and it recognized my drive.
Also... DVDA does not work with ALL makes of DVD drives... a bit of a pain I guess if you bought one that it doesn't support. There is a list of supported drives on this site somewhere... I'm sure you will find it if you go looking.
Although I build/prepare all my DVD's in DVDA2 I actually normally burn my DVD's with another product anyway. If your bruner came with some burning software you can very likely just load the prepared folders from DVDA into that program and burn from there. I use Recordnow DX which came with my Pioneer.