Well depending on how your Admin set up Autodesk Licensing depends on how you authenticate the license. We are running the 2007-2008 Autodesk suite (Viz, Inventor, Auto CAD, etc). We have 4x unlimited seat licenses, one for each high school. I didn't want to mess with setting up a license server, nor did I want to sacrifice a machine for a license server since we have an unlimited seat license I chose to have them authenticate license files online. IE 7 breaks this, and it took me a while to figure this out. Vista only runs IE 7, and Autodesk requires IE to authenticate the license, so you are kind of just up the creek with no paddle with Vista.
So, I thought I would give you a heads up.