mftrace segfaults on cmex9

Binary package hint: mftrace

When I typed "mftrace cmex9", I got
=========================
Segmentation fault
error: fontforge: command exited with value 35584
Traceback (most recent call last):
  File "/usr/bin/mftrace", line 1412, in <module>
    main()
  File "/usr/bin/mftrace", line 1408, in main
    do_file (filename)
  File "/usr/bin/mftrace", line 1391, in do_file
    make_outputs (basename, options.formats, encoding)
  File "/usr/bin/mftrace", line 864, in make_outputs
    shell_escape_filename (raw_name), shell_escape_filename (options.tfm_file)))
  File "/usr/bin/mftrace", line 172, in system
    error (msg)
  File "/usr/bin/mftrace", line 114, in error
    raise _ ("Exiting ... ")
TypeError: exceptions must be classes or instances, not str
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instead of the usual result.
I'm using Karmic, Version 1.2.14-2 of mftrace and Version 0.0.20090622-1 of fontforge.
Any help would be appreciated.
Thanks, -Daniel W.