Comment 5 for bug 208433

And one more from the list;

Do some of you guys mind downloading and testing with dependency walker from here;
http://www.dependencywalker.com/

Run that and then Open the Inkscape executable. Under the view menu, select Full Paths. This will show you where you're getting your libs from.

Also, can I ask whether you used the installer version, or one of the zip/7z versions? I think the installer adds a path entry for the directory. The inkscape executable should dynamically modify paths, but it may not be fixed properly. If you have trouble running extensions, that is a sign your path setting isn't right. If that's the case, are you running as administrator? Don't know about Vista, but on XP this may affect your access to certain path related registry settings.