Bummer. Are they not compatable with vista 64? Trying to run the widescreen mod it says publisher cannot be verified. When I say ignore that, it just thrashes. The other mods act similar.

I'm still on WinXP, and haven't searched to see if anyone else ever had these problems, but did you try to run them as admin? If the game is installed in the Program Files directory, you'll probably have no choice but to run the installers with admin privileges.

That's the first thing that comes to mind anyway.

You will save yourself a lot of grief, if you reinstall the game outside of the ProgramFiles(x86) directory.
In the gog installer choose options & create a C:\Games\Planescape directory.
Also disable your antivirus active scanner while installing the mods.