gdb internal error

Hello everybody!

I have a problem when debuging multithreaded program written with pthreads. 
gdb fails with message:

lin-lwp.c:1167: gdb-internal-error: lin_lwp_wait: Assertion `lp->resumed' 
failed.
An internal GDB error was detected.  This may make further
debugging unreliable.  Quit this debugging session? (y or n)

Program uses pthreads.
My system is Linux Mandrake 9.1
2.4.21-0.18mdk
glibc-2.3.1
gdb 5.3-22mdk

Is it because of a problem in my code or because of an error in gdb? 
Thank everebody for any help.