gdb-mode hangs in OS X

[Michael Lee]

I'm having an issue under OS X and emacs version 22.0.50.1 where 
entering any command at all in gdb-mode after getting into it with M-x 
gdb causes the buffer to "hang" (it just sits there without producing 
any output or accepting input) --- I can get back to a gdb prompt with 
C-c C-c, but can't even type quit to exit gdb.

The symptoms are similar to those exhibited by shell mode without (setq 
process-connection-type t).

Any ideas?

Thanks,

Michael