finder-commentary doesn't works with compressed files

starting from C-h p (finder-by-keyword), if i first select a keyword, and then i select, with button2, a library description, i get the following: Signaling: (error "Can't find any Commentary section") signal(error ("Can't find any Commentary section")) cerror("Can't find any Commentary section") apply(cerror "Can't find any Commentary section") error("Can't find any Commentary section") finder-commentary("lisp-mnt.el") finder-select() finder-mouse-select(#<buttondown-event button2>) call-interactively(finder-mouse-select) i have all my .el sources gzipped, so i i tried to uncompress the relevant source file, to find that finder-commentary works fine apparently, finder-commentary works fine with uncompressed sources only