Firefox/pango/cairo

[Motor]

When I upgraded to FC5, I noticed that Firefox was especially slow. I
solved it by using this:

export MOZ_DISABLE_PANGO=1

After updating firefox to 1.5.0.4 via yum recently... Firefox is now back
to being really sluggish and irritating to use (on a AMD XP 2000+, 512Mb
RAM, with a Matrox G550 card). Has this non-Pango option now been removed?

It would be very irritating if it has, since FC5 and the use of Cairo for
GTK, my GTK/GNOME apps have all been appalling to use. The apps redraw
like an old 486 with Windows 3.x. The few Qt apps I run are unaffected.
Frankly, it's embarrassing to show to others.