(gdb) bt
#0  0xffffe410 in __kernel_vsyscall ()
#1  0xb7e35986 in ?? () from /lib/tls/i686/cmov/libpthread.so.0
#2  0x0811c032 in _wapi_handle_spin (ms=100) at ../../mono/io-layer/handles-private.h:314
#3  0x0811c3ea in _wapi_handle_timedwait_signal_handle (handle=0x40c, timeout=0x0, alertable=1) at handles.c:1488
#4  0x0811c28b in _wapi_handle_wait_signal_handle (handle=0x40c, alertable=1) at handles.c:1453
#5  0x0812e145 in WaitForSingleObjectEx (handle=0x40c, timeout=4294967295, alertable=1) at wait.c:200
#6  0x080e4235 in ves_icall_System_Threading_Thread_Join_internal (this=0x21578, ms=-1, thread=0x40c) at threads.c:837
#7  0xb6b45aed in ?? ()
#8  0x00021578 in ?? ()
#9  0xffffffff in ?? ()
#10 0x0000040c in ?? ()
#11 0x08243090 in ?? ()
#12 0xb6b450d0 in ?? ()
#13 0x0005c3c0 in ?? ()
#14 0x00000000 in ?? ()