GDB doesn't like IRIX's pthread library?

When I compile a simple program and run it in GDB v5.3, it executes just fine. Then I add
-lpthread to the compilation.  When I run the program using GDB, the debugger will lock
up.  I have to manually kill the process.  Note that the program will execute just fine
outside of gdb.  Here's the output:

bash-2.04$ g++ test.cpp -lpthread -o test
ld32: WARNING 84 : /usr/lib32/libpthread.so is not used for resolving any symbol.
ld32: WARNING 84 :
/home/me/Builds/bin/../lib/gcc-lib/mips-sgi-irix6.5/3.2/../../../libstdc++.so is not used
for resolving any symbol.
ld32: WARNING 127: Two shared objects with the same soname, /usr/lib32/mips3/libm.so and
/usr/lib32/libm.so, have been been linked. This is probably due to a missing -L
specification. Ignoring the latter.
bash-2.04$ gdb ./test
GNU gdb 5.3
Copyright 2002 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB.  Type "show warranty" for details.
This GDB was configured as "mips-sgi-irix6.5"...
(gdb) run
Starting program: /tmp_mnt/home/me/Confused/GDB_Problems/test 
warning: Signal ? does not exist on this system.