Sub 2 hour video over 5.1 gig..
 

Im rendering out of Vegas 8.0 for dvd widescreen. One edited video track, 5 transistions, two audio tracks and 1:56 min timeline. I cant get here to less than 5.1 gig and DVD architect wont compress... Help me Obi Wan Kenobi....Your my only hope

You are talking about Vegas Pro 8, correct?
And you're rendering AC-3 audio?
If so, render again from Vegas but use either of the following bitrate settings.
I guarantee these will work for you as I just finished rendering two different shows using these numbers and had no problems getting it onto a single-layer DVD.
You will need to go into the Custom and then Video tab in Vegas and change the numbers to these settings.
Once done, save them as a 2 hr. DVDA preset so that it can be used again and again.

CBR: 4,576,000
VBR: 8,000,000 / 4,576,000 / 2,744,000

What format are you rendering out as?

Rendering out as
 

mpeg2 for dvd architect widescreen

William, as Mike said you need to adjust the bitrate. You haven't yet said what VERSION of Vegas you're using (other than "8") Is it 8 Pro? or is it 8 Movie Studio? The Movie Studio versions don't let you set a custom bitrate for MPEG2 while the Pro version will.

As far as DVD Architect is concerned, it should recompress as needed if it's too large.