recent iceweasel desktop switching problem

["Russell L. Carter" <rcarter@pinyon.org>]

Hi Folks,
First, I'm not sure I have the diagnosis right so if my description
is wrong I would appreciate tips on how to improve it.

I'm on testing (wheezy) and I'm using fvwm, as I always have for
the last 20 years (not sure I should admit that).  Comparing
5 browsers:

stock testing: iceweasel 3.5.19-3

squeeze backports: iceweasel release
squeeze backports: iceweasel beta
squeeze backports: iceweasel alpha

stock testing: chromium  12.0.742.112~r90304-1

The problem is that when using the squeeze backports iceweasel versions,
when I click on a URL with mouse-2, it switches me to the fvwm desktop
directly below the active desktop, instead of opening a new tab with
the URL.  both stock testing iceweasel and chromium work fine, as they
always have.

First, am I asking the right question?  Is this possibly a change in X
mouse bindings?  If it is the right question, how do I teach the squeeze
backports iceweasel versions to do the right thing on mouse 2 on a
URL (open a new tab with the URL contents).

Thanks,
Russell