Comment 53 for bug 239826

tweaking summary to catch dupes better.

You can get around this bug with the web developer toolbar's "View Source" or by manually prepending "view-source:" to the blocked URI, eg:
  view-source:http://www.mozilla.com/firefox/its-a-trap.html

Either way will get you the malware block but since it's in a normal tab/window you'll have a working "Ignore Warning" link. Since none of the buttons work on a malware block in the view-source popup I'm guessing it's simply not got the event-handling code for them (it's not a normal browser popup window, note how the menu is different and there's no location bar).