Gimp.app 2.2.10 twain is broken, but don't fret the fix is easy.
I reported this bug to sourceforge and got a reply in a day.
The author of the fix didn't give his/her name, but thanks was offered for the helping hand.
I know this topic won't get many hits, but I wanted this fix here so some poor soul looking for a solution can find it through the search function.
(Mucommander makes it easy to find these files)
The full text
"Date: 2006-01-20 00:52
Sender: nobody
Logged In: NO
Crap... sorry about that. The problem is that HFS+ is case
insensitive. There is a
symlink in Gimp.app/Contents/Resources/lib called libtiff.dylib
and libpng.dylib.
These get loaded instead of the system's libTIFF.dylib and
libPng.dylib. If you
delete those two symlinks under Resource/lib, everything works
fine."
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