I'm on a Mac and would like to tell you, but I'm a Mozilla user. Left the PC for the Mac three years ago and haven't looked back, thus what sense would it make to use IE? But I can say that the popups do work great in the Mac version of Mozilla.
I remember a day when webmasters coded pages with clean, non-specific platform and browser code and kept concern that it should work with all of them, and these days, it's a "I'll just code for IE" mentality that's sloppy and shouldn't be followed, IMO. (It's like opening a highway and only letting Chevy owners use it) Good code is cross-compatible, whether you're IE, Netscape, Mozilla, Opera or Lynx (well, I doubt Lynx will ever be an optimal choice for NG, but you get my drift) :P
Kudos to you making all of NG's features accessible to everyone and your efforts are appreciated.