It sounds like this directory has become corrupted (it is a database, and thus the mine files may not show up as files). The usual solution is to delete the C: \ Users \ MP \ AppData \ Roaming \ Fritzing directory and let Fritzing recreate it (you may want to just rename it to save a copy and let Fritzing create a new one). Note this may break any new parts that you have added (and it sounds like you have added a lot) so you may have to reinstall them all again. I believe you can create libraries of parts files (that is what adafruit does I think), but I haven't done it and don't see any obvious documentation (perhaps someone else has a pointer?).
(edit:) It looks like what adafruit did is export an entire bin. That forms the fbz file and apparantly can be re imported as a group. I expect that you move the parts you want in to a new bin and then export that.
Peter
