Trouble with IGES export

While exporting a file to IGES, I encountered a FPE. The file is attached, and the DRAWEXE transcript follows:

Draw[1]> pload ALL
Draw[2]> restore gear_test.brep s1
s1
Draw[3]> brepiges s1 tmp.igs
An exception was caught 0xb62f7361 : Standard_NumericError: SIGFPE Arithmetic exception detected
** Exception ** 0xb62f7361 : Standard_NumericError: SIGFPE Arithmetic exception detected
Draw[4]>

Is there something illegal about the shape, is it clean on other compilations, or is this an OCC bug? I managed a workaround by simply exporting to STEP, so it's not a critical issue for me. I thought OCC developers may want to be aware of it, if it is an OCC bug. I'm using OCC 6.3, so it might be fixed in 6.5.2.

The error was first encountered under pythonocc. In that case, the file was written but the extruded spline portion of the gear teeth didn't show up when I viewed the IGES file. That may be the problem area.

Thanks,
Charles