I'm calling an ocaml function from C, with the following statements:

{  ... /* setup args */

   if (fn_closure == NULL)
     fn_closure = caml_named_value ("fn");

   answer = callback3_exn(*fn_closure,
		     Caml_rep, Caml_tofile, Caml_codefile);

   if ( Is_exception_result( answer ) ) {
     retval = NULL;
     CAMLreturn( retval );
   }

   if (Is_block(answer)) {
	... /* handle result */
   }
}

Using callback3_exn should catch any exceptions thrown in the code and 
return. However, when the caml code throws an exception, my code doesn't 
get control and the program terminates! I don't understand what's wrong 
here -- could somebody please help?

Thanks,

Richard Samuels
rls25@cornell.edu