Firefox/Iceweasel 3: agony of the snail

[Jim McCloskey <mcclosk@ucsc.edu>]

An upgrade to testing this afternoon unexpectedly brought me
Firefox/Iceweasel 3.0, which was fairly exciting. Here, though, it is
just agonizingly slow---10-12 seconds between clicking `Bookmarks' in
the Toolbar and the display of the menu. Scrolling through:

  http://lists.debian.org/debian-user/2008/07/thrd4.html

is like wading through thick, thick mud. When one moves from screen to
screen, iceweasel/firefox takes about 7 or 8 seconds to redraw its
window. It's really unusable.

Is anyone else seeing this?

Epiphany behaves similarly, but Konqueror and Mozilla are wonderfully
fast, suggesting that the problem (whatever it is) lies with Gecko.

This last suspicion was confirmed when I installed epiphany-webkit and
called it explicitly. It was just as fast as Konqueror and Mozilla.

Upgrading to 3.0.1 in unstable makes matters, if anything, worse.

Downgrading to version 2.0 in stable restores normal speed and usability.

The problem is the same in the binary version available directly from mozilla.org.

sigh

Jim