Can't run iceweasel [Couldn't load XPCOM]

[Harry Putnam <reader@newsguy.com>]

I see old bugs from 2011 where this problem is claimed to be solved
but I'm getting the problem now on wheezy.

After installing iceweasel, when I try to run it:

,----
| XPCOMGlueLoad error for file /usr/lib/xulrunner-10.0/libxpcom.so:
| libxul.so: cannot open shared object file: No such file or directory
| Couldn't load XPCOM.
`----

Version info:

,----
|  aptitude search -F '%p %v' '?installed'|grep xulrunner
| xulrunner-1.9.1              1.9.1.16-16   
| xulrunner-10.0               10.0.5esr-1   
| xulrunner-dev                10.0.5esr-1   
`----

Do I have something installed that should not be?  It looks like 2
versions are installed.