So, I went to purchase the ACADLT 2009 for use on my new Vista OS and found the requirement that I can only use the upgrade version to go from 2006 or newer to 2009.  Is this in fact true?  Any one know of a work around to get my LT2004 to upgrade?  Or am I stuck purchasing the full price version?ThanksArthur

Yes, the older versions of CAD applications are no longer upgradable. Your Autodesk authorized dealer may give you more information how to legacy-upgrade your LT.