We've recently moved to running Fogbugz over https which work amazingly easily.
One annoying quirk though is that the screen capture plugin does not follow the redirect from the old http:// to the new https:// address. As a result it throws a hundred and one javascript errors as it tries to load the Fogbugz homepage in the little pop up window.
Simple fix (once I'd clicked through the 50+ error pop ups, damn you IE) is to right click on the screen capture icon in your quick launch bar, select Options and change the url it posts to to use https://
Cheers
Pete