I bought the latest version of Microsoft Streets & Trips over the weekend, and after I installed it I kept getting error messages about the map data being the wrong version. I uninstalled, reinstalled, made sure the folder under Program Files was gone, all to no avail. Finally it occurred to me to check the AppData\Virtual Store folder in my user profile.
If you run a program under a standard user account and the program tries to write to a protected area, it redirects those writes to a per user space. Turns out that removing the old version of Streets & Trips left those per user files behind, so whenever the program ran, it looked at the old data files and not the new ones. Removing the Streets & Trips folder in VirtualStore cleared up the problem.
Microsoft has a Knowledge Base article (KB 927387) that talks about common issues related to file and registry virtualization. God reminder about Vista nuances.