Version 0.61 has now been uploaded to
the first post of the thread.
This includes all recent fixes for the scripts, and now should fully support the use of unicode file names, thanks to lots of work by KevinH.
With version 0.61 the name of the scipt has been changed to KindleUnpack, since almost all Mobipocket files are now actually Kindle files from Amazon, and the script certainly handles files that are not Mobipocket at all (KF8 and .azw4).