@Sassy; one option would be if you have a USB memory stick to install a copy of calibre Portable to it; Portable is totally independent of the settings on the regular calibre and you could at least try a conversion / load of a book that way.
Have you tried any of the
Mobi files from the
Patricia Clark Memorial Library here at MobileRead; this could maybe let others with a KF try the same book and see what happens. Next step could be to try an
ePub from the library here and convert it to Mobi, and again have another KF user try the same book and conversion.