Here's what Vegas does. I'm editing along just fine in Vegas, using my monitor via firewire, I open DVDA to burn a DVD, instantly, DVDA takes over my monitor with a blue screen, I guess DVDA production screen. So my question, is Vegas just getting confused?

How many monitors is in your setup? I have 3 monitors and sometimes the application jumps to the third monitor and comes across all three screens and I only see the middle or far right side of the window which is blue. But I just tried your problem on my deck and have no problems with both programs running. You might have to reinstall DVDA to see if it solves the problem.

Via Firewire, I only have the one production monitor setup. For instance; if I am editing using the production monitor via firewire, and I open DVDA to burn a dvd, DVDA will take over the production monitor preview and not give it back to Vegas until I close DVDA. It's odd, and annoying. This doesn't affect my pc preview at all.

Steven, I stand to be corrected but, as I recall, if you de-select the "close media files when not the active application" box in Vegas (Options - Preferences - General), this should allow Vegas to remain active when you launch DVDA while Vegas is still running.
The other thing to try is disabling the external preview function in DVDA.