I had the same as I removed my music directory and I even closed CF before doing that and recreated an empty directory with the same name before restarting CF.
As it kept crashing I deleted the whole profile and then it worked again, altough I had to re-configure every setting again of course.
Same happens when you reformat your ipod and load all the songs on it again, since the directory structure changes then.
Although CF is a great product and running quite stable now, I really hope that the developers look into exception handling in the near future as CF "crashs + running in shell mode" is a very nasty combination...
