The quickest and easiest way I have found to get a working TOC in a mobi file is by converting it to epub, letting Sigil create the TOC (make sure it's not multi-level), then converting back to mobi. I get a perfect TOC, with the jump-ticks this way.
I know it's cheating
but, like Lazer, I find the mobi-creation tools to be a PITA.
Regarding calibre-created files and DRM, Kovid recently changed the code to add in the empty space Amazon required for it, so that's not supposed to be an issue anymore.
