malloc dropped core

While using ImageMagick, I got the following error message

troutmask:kargl[209] display case3b-wth-longrange.jpg 
Assertion failed: (mapelm.free == false), function arena_dalloc, file /usr/src/lib/libc/stdlib/malloc.c, line 2440.
Abort (core dumped)

Unfortunately, the backtrace doesn't give too much info

#0  0x00000002027b321c in kill () from /lib/libc.so.7
#1  0x0000000200720fed in MagickSignalHandler ()
   from /usr/local/lib/libMagick.so.10
#2  <signal handler called>
#3  0x00000002027b321c in kill () from /lib/libc.so.7
#4  0x00000002027b20ad in abort () from /lib/libc.so.7
#5  0x000000020279bc25 in __assert () from /lib/libc.so.7
#6  0x0000000202743b2f in reallocf () from /lib/libc.so.7
#7  0x0000000202745cc7 in free () from /lib/libc.so.7
#8  0x000000020072244e in RelinquishMagickMemory ()
   from /usr/local/lib/libMagick.so.10
#9  0x00000002006ca98b in XMagickCommand () from /usr/local/lib/libMagick.so.10
#10 0x00000002006da20b in XDisplayImage () from /usr/local/lib/libMagick.so.10
#11 0x0000000200acacf2 in DisplayImageCommand ()
   from /usr/local/lib/libWand.so.10

On this system, I have /etc/malloc symlinked to aj.
libc and kernel are from 7 Feb 07 sources.

-- 
Steve