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.
Did you check the directory permissions? ImageMagick typically puts it files in /usr/local/lib/lmageMagick-6.2.8. Check the permissions on this directory and any subdirectories. If that fails, type
convert -debug configure logo: logo.pnm
It will tell you where its looking for its dependant files.