Hmm, possibly go into:
C
Program Files\Graal\Levels\* and delete all relevant folders.
The ones you should delete are:
Heads and images. This should clear the problems up. What should happen is when you start up Graal and go on the the servers, the graphics will re-download, hopefully, with the correct graphics.
Note: It could take a short while for everything to download, if it seems like everything stopped, reconnect to the server to make sure you have everything.