Huh? That seems complicated.
I convert doc and docx to prc just by dropping them in Mobipocket Reader. I've never had any problems. That's the quickest route I know. The conversions show up in C:\[user_path]\Documents\'My eBooks' on Vista. Second best is to email them to Amazon to
XXXX@free.kindle.com. It works equally well for rtf, which is what I use for web scraping.
I do have Word on my machine, so it's possible MR is using that to convert to HTML 3.2 before writing a file. I've never tried it on a machine without Word. (My company gets us Office 2010 for cheap so we can work for them for free at home.)
One of my pet peeves about format conversions is that most routes take a lot of extra steps. I only use Calibre's CLI methods, if I use it at all.
Regards,
Jack Tingle