core dump on reloading code

[Matt Wette]

If I start up guile and load some code it seems to run OK.
If I load the code a second time, it core-dumps.  Here is
the gdb output.  If you have any clues on this one I'd 
appreciate it. -- thanks, Matt

guile version is 1.4

head of config.status is
  # ./configure  --prefix=/opt/guile --with-modules --with-readline 
    --enable-ltdl-convenience


Starting program: /opt/guile/bin/guile 
guile> (load "a1-model.scm")
TBD: define/solve frame lineup problem
TBD: define light sources
guile> (load "a1-model.scm")

Program received signal SIGILL, Illegal instruction.
0xb0c20 in ?? ()
(gdb) up
#1  0xff2c8b00 in scm_igc (what=0xff356b18 "cells") at gc.c:891
891       scm_gc_sweep ();
(gdb) list
886       scm_gc_mark (scm_root->handle);
887     #endif
888     
889       scm_c_hook_run (&scm_before_sweep_c_hook, 0);
890     
891       scm_gc_sweep ();
892     
893       scm_c_hook_run (&scm_after_sweep_c_hook, 0);
894     
895       --scm_gc_heap_lock;
(gdb) list 880,890
880       /* FIXME: we should have a means to register C functions to be run
881        * in different phases of GC
882        */
883       scm_mark_subr_table ();
884     
885     #ifndef USE_THREADS
886       scm_gc_mark (scm_root->handle);
887     #endif
888     
889       scm_c_hook_run (&scm_before_sweep_c_hook, 0);
890     
ZZ