For every source of images that you set, PCafe creates a file in ..\Program Files\PhotoCafe\ImageLists Even though this file has a *.pcl extension, it is just a text file. It sounds like PCafe is having a hard time with a particular file or folder. Normally it should just ignore files it has problems with, but if you crate the error in the pcl file that may be a source of the problem.
Open the created *.pcl file and see if anything looks odd to you. You can post it here if you wish and I'll look at it.

Thanks for the help, anyway.