Image title tooltip (not alt text) doesn't work
There are half a dozen or so existing help requests mentioning alt text or discussing problems with the Google Toolbar add-on, but this is not my issue, so I am opening a separate help ticket.
If you are here about "alt" text, first read any of the posts explaining that "alt" text isn't supposed to appear, it's just a quirk of IE that it sometimes does, FF4 is correct and does what the standards ask and what other browsers do. You want "title" text. The best explanation seems to be: https://support.mozilla.com/en-US/questions/804893
If you have the Google Toolbar installed, turn it off and see if you get them back. This is a known issue, eg: http://support.mozilla.com/en-US/questions/740139
See also: https://support.mozilla.com/en-US/questions/803441 https://support.mozilla.com/en-US/questions/775410 https://support.mozilla.com/en-US/questions/802284 https://support.mozilla.com/en-US/questions/751043
Now, still not getting tooltip popups for here or here? http://www.xkcd.com/ http://www.asofterworld.com/
Neither was I. I *did* get them in safe mode, but I did a lot of resetting and mucking about without any luck. In the end, after doing a text diff between safe mode and not, of the Troubleshooting information (in the Help menu), I found that the issue might be Direct2D-related, and changed the flag "gfx.direct2d.disabled" to true in about:config. I now have tooltips back but a less efficient FF4.
Hope that this helps someone, and hope that the Direct2D issue gets sorted out!