Crash tracking ?

Hi, Anybody's got an idea on how to find why XEmacs is crashing when using Gnus ? This is triggered by gc, so it is quite random. I have always the same crash address, so I have put a breakpoint on it, and this address is first modified in the following context : adjust_extents(int 568336896, int 735, int 65360, int 4460) line 2330 + 129 bytes gap_left(buffer * 0x01e02200, int 735) line 1713 + 42 bytes buffer_delete_range(buffer * 0x01e02200, int 710, int 735, int 0) line 2680 + 13 bytes Fdelete_region(int 710, int 735, int -1582282748) line 1841 + 19 bytes Fbyte_code(int 1644174984, int -2117995776, int 8) line 1005 + 22 bytes funcall_lambda(int 568903260, int 1, int * 0x0082e6f8) line 3599 + 35 bytes funcall_recording_as(int -1578708028, int 1, int * 0x0082e6f4) line 3200 + 20 bytes Ffuncall(int 2, int * 0x0082e6f4) line 3238 + 19 bytes Fbyte_code(int 1647058796, int -2112734720, int 7) line 416 + 16 bytes funcall_lambda(int 571968752, int 2, int * 0x0082f144) line 3599 + 35 bytes funcall_recording_as(int -1575517628, int 2, int * 0x0082f140) line 3200 + 20 bytes Ffuncall(int 3, int * 0x0082f140) line 3238 + 19 bytes Fbyte_code(int 1645380512, int -2114050560, int 5) line 416 + 16 bytes funcall_lambda(int 571915896, int 5, int * 0x0082f45c) line 3599 + 35 bytes funcall_recording_as(int -1575517652, int 5, int * 0x0082f458) line 3200 + 20 bytes Ffuncall(int 6, int * 0x0082f458) line 3238 + 19 bytes Fbyte_code(int 1645380236, int -2112389760, int 7) line 416 + 16 bytes funcall_lambda(int 571915840, int 5, int * 0x0082f86c) line 3599 + 35 bytes funcall_recording_as(int -1578708532, int 5, int * 0x0082f868) line 3200 + 20 bytes Ffuncall(int 6, int * 0x0082f868) line 3238 + 19 bytes Fbyte_code(int 1644187092, int -2113947392, int 6) line 416 + 16 bytes funcall_lambda(int 570454160, int 1, int * 0x0082fa84) line 3599 + 35 bytes funcall_recording_as(int -1577129044, int 1, int * 0x0082fa80) line 3200 + 20 bytes Ffuncall(int 2, int * 0x0082fa80) line 3238 + 19 bytes Fcall_interactively(int -1577129044, int -1582282748, int -1582282748) line 935 + 22 bytes Fcommand_execute(int -1577129044, int -1582282748, int -1582282748) line 2584 + 17 bytes execute_command_event(command_builder * 0x01bff340, int 565531200) line 4346 + 25 bytes Fdispatch_event(int 565531200) line 4645 + 71 bytes Fcommand_loop_1() line 579 + 9 bytes command_loop_1(int -1582282748) line 495 condition_case_1(int -1582282652, int (int)* 0x01033216 command_loop_1(int), int -1582282748, int (int, int)* 0x01032cc4 cmd_error(int, int), int -1582282748) line 1653 + 7 bytes command_loop_3() line 256 + 35 bytes command_loop_2(int -1582282748) line 268 internal_catch(int -1582172356, int (int)* 0x01032e14 command_loop_2(int), int -1582282748, int * 0x00000000) line 1328 + 7 bytes initial_command_loop(int -1582282748) line 305 + 26 bytes STACK_TRACE_EYE_CATCHER(int 1, char * * 0x01bff880, char * * 0x01c07000, int 0) line 1702 + 9 bytes main(int 1, char * * 0x01bff880, char * * 0x01c07000) line 2119 + 21 bytes mainCRTStartup + 211 bytes _start() line 118 But I have no idea on how to investigate further. This is with 21.0-b46 native build under NT. Fabrice