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.
The following does not seem preserve the transparency in IM 6.9.1.7 (and the white color is changed). The image has fully opaque transparency. It works fine if PNG or TIFF