Parts of skin seem to be missing..
I'm pretty new to all this but am having a great time with Windows Blinds and skins made by people with more talent and time than I have.
One thing I've noticed is after I apply many of the skins that are out there, they look great accept for a few graphics that seems to be missing and are replaced with solid purple color. In particular the center of the vertical scroll bar and a few other parts of internet explorer.
Like this:

Is this the
the fault of the skin maker forgetting to make a few parts or is this something I can fix. Many times this issue has ruined an otherwise beautiful skin.
Thanks.