The mobi output from Calibre is having display problems with the Kindle PaperWhite (I can confirm as an owner) and these are supposedly also happening with the Touch and have been for a while. This is almost certainly an issue for the Mac as well as Windows version because it’s, more or less, a KF8 issue.
The issue is font sizing. Apparently if you pass a font size or type definition to kindlegen, it creates problems on some devices. The symptoms are an unchangeable font or a teeny tiny font. In my case, the TOC was fine in the Scrivener created mobi, but the text of the story came out teeny tiny. In my case, every book I’ve compiled with Scrivener is essentially unreadable on a touch or paperwhite.
The short workaround for authors reading this is to run them through Calibre and convert mobi to mobi.
Here’s the rub: these issues only show on on the devices, not on the kindle previewer.