Since Sun released 2.0, one of the most frequent complaints we've had is
from people who've tried to install new themes and failed, usually (but not
always) because the directory structure in the tarball was wrong.

We need to do a much better job of detecting whether a theme installation
has been successful or not, and telling the user what went wrong if it
wasn't.  Right now about the only way to tell is how long the "Install New
Theme" dialog stays up... if it stays up a long time the installation was
usually successful, if it disappears straight away it wasn't :)