This can happen for a couple of reasons.. 1 its a hack copy.
2. there is a file in directory c:\documents and settings\applications that needs to be deleted because of corruption.. don't remember the file name and Gibbs isn't on my home PC, so I can't look it up.. but the gibbs people are very helpfull and can tell you over the phone how to fix it.
ps the file will be remade when you open gibbs again. and walla!