Is this a bug in gdb?

[walt]

I'm trying to debug the recent problem with firefox, but I'm
having trouble running it with gdb (on HEAD):

(gdb) run
Starting program: /usr/pkg/lib/firefox/firefox-bin

Breakpoint 1, main (argc=1, argv=0xbfbff900) at nsBrowserApp.cpp:60
60      {
(gdb) c
Continuing.
gdb in realloc(): error: irealloc: pointer to wrong pageAbort trap
$ <and then I'm back at the shell prompt>

On the other hand, if I don't set any breakpoints, I see this:

(gdb) run
Starting program: /usr/pkg/lib/firefox/firefox-bin

Program exited with code 01.
(gdb)

Anyone understand what's going on here?