imagemagick/montage problem

hi everybody, attempting to use `montage' from teh imageMagick package with something like montage -tile 2x2 i1.png i2.png i3.png i4.png leads to a crash with the error message magick/cache.c:2385: failed assertion `cache_info->number_views != 0UL' this is with version ImageMagick 6.2.7 08/29/06 installed in the 'old' darwinports times, but this seems to be the current version, still. I tried the same with the most recent version provided via fink (6.1.8 08/28/06): there, everything runs smoothly. any ideas appreciated. regards, joerg