Xlib: Maximum number of clients reached -- firefox?

[Joshua Baker-LePain <jlb17 duke edu>]

I'm rather happily running FC6 on my Thinkpad Z61t.  I got even happier 
when I discovered that suspend works without a hitch, with no pre-suspend 
fiddling required.  On resume, everything comes back up including my 
WPA-encrypted ipw3945 wireless connection, and this with my HDD in AHCI 
mode.  All very, very shiny.

So I haven't shut down or logged out in a week.  Today, though I started 
getting errors like this upon trying to start new apps:

Xlib: connection to ":0.0" refused by server
Xlib: Maximum number of clients reached

'xrestop' takes an absurd amount of CPU time to run, but seems to indicate 
that firefox has a huge number of windows open (over 2500).  I certainly 
don't have that many windows/taps actually open, but I also haven't shut 
down firefox in almost a week.

Is this a firefox bug that needs reporting?  If not, where should I be 
looking?

Thanks.

--
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University