Firefox has recently released version 4. Unfortunately, the online version of Genii doesn't work in it, on Windows XP. I can log into Ask Alexander, click the cover of the issue in the lower-left, the second window pops open, the icons appear on the left edge, but I never see the cover of the issue.
Chrome is now up to version 10, it's fine. I haven't had a chance to try IE 9, it's not available for XP.