You're welcome.
To answer your questions: I used the command line tool Mobigen to create the mobi file (you can get it from
Mobipockets Developer Center). The mobi file it creates should be the same as the one created with Mobipocket Creator -- you can rename filename.prc to filename.mobi and the other way around if you want. I don't know why Mobigen defaults to filename.mobi and Mobipocket Creator to filename.prc, but it doesn't matter anyway.