Chroot for FC9 - firefox opens a window instead of new session

[B Wooster]

On a x86_64 Linux machine, I made another x86_64 chroot environment
for FC9, and installed a 32-bit firefox in the chroot. The main host
has as 64-bit firefox, old one - 1.5.x something (BonEcho).

When I enter the chroot, and log in as root, I can start the 32-bit
firefox. This opens up a new session and all is fine.

When I enter the chroot, and log in as the same user as that in the
parent host, then I'm unable to start a new firefox - it always starts
up a window to the original firefox.
And I can't even start a new instance - it always seem to start the
the firefox from the original host - which is extremely confusing. I
tried the --no-remote option to Firefox 3.0.3, that firefox
immediately exits in the chroot.

The chroot environment shares /tmp and hence all of X display with the
main host. Is there a way to trick firefox into not locating the
firefox running outside the chroot? I suspect it is the sharing of the
tmp folder that allows firefox to get at this info., But I need to
share the /tmp to make X11 work well in the chroot.

Any tips/suggestions appreciated.