Using Firefox 1.0. STEP TO REPRODUCE: 1. Enter a non-existent domain into the URL bar (such as might result from hitting ENTER too early while typing in bugzilla.mozilla.org for instance). E.g., "bugz" and press ENTER. 2. Now realize your error and try to stop Firefox from attempting to look up that address. RESULTS: You cannot stop Firefox until it errors out. EXPECTED: Stop should work during DNS.
Just wanted to point out a couple of additional points that make this issue more aggregious: 1. DNS activity blocks activity in all open Firefox windows. Very annoying. 2. More common than non-existant domains, is non-reachable domains. This problem can happen frequently for VPN users.
The same is still happening on 18.104.22.168 under Linux. This bug has been opened for over 2 years !!! 8( I think that, before relesing 2.0 and thinking about 3.0 (see http://wiki.mozilla.org/Firefox/Feature_Brainstorming) Bugs should be corrected! This is a very annoying bug I hit almost once a week. Firefox hangs for about a minute, no tab reacts, rendering is blocked!
You might try your luck over at GNUzilla and the Iceweasel project: http://savannah.gnu.org/projects/gnuzilla/
This issue seems fixed in Fx 3.6.4.
This issue is fixed.