xwd from the XFree86 package and convert do not fit together; using the
following command to take screenshots shows what I mean:

$ xwd -root > /tmp/root.xwd; convert -colors 65535 -quality 90 -interlace
none /tmp/root.xwd $HOME/root.jpg
convert: XWD file format version mismatch (/tmp/root.xwd) [No such file or
directory].
convert: Missing an image file name.

Looking into ImageMagick's sources reveals that this message will be
emitted, if the compile time constant XWD_FILE_VERSION from
/usr/include/X11/XWDFile.h is not equal to what is found in the image's
header. Rebuilding the package using

# rpm --rebuild ImageMagick-5.2.2-5.src.rpm

fixes this.

HTH, cheers.

l8er
manfred