Post any defects you find in the released or beta versions of the ImageMagick software here. Include the ImageMagick version, OS, and any command-line required to reproduce the problem. Got a patch for a bug? Post it here.
How are you decoding the DIB's with ImageMagick? There are three or four different places in ImageMagick that read DIB's and apparently one if out of sync with the more robust BMP reader. Is there a small piece of code or script that you can post so we can reproduce the problem and patch ImageMagick to work properly.