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.
I'm not so sure if this is an actual bug, since one of the operations generates values out of range... nevertheless I'm reporting it for you to appreciate.
Apart from this small bugs I've found ImageMagick is doing an excellent work in HDRI post processing, mixing results from a bunch of tonemappings, etc...
Together with pfstools makes one of the most powerful toolchains for HDRI processing.