“expr: syntax error” with acroread

I installed acroread (BTW it’s called “Adobe Reader”, not “Adobe Acrobat Reader”) on Ubuntu Gutsy from the Medibuntu repository, and running acroread gave lots of

expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error
expr: syntax error

in an apparent infinite loop.
Googling gave this link but it seemed to already have been fixed in the version I had.

Another link gave the clue:

The line that reads:
echo $mfile| sed ‘s/libgtk-x11-\([0-9]*\).0.so.0.\([0-9]\)00.\([0-9]*\)\|\(.*\)/\1\2\3/g’
should be
echo $mfile| sed ‘s/libgtk-x11-\([0-9]*\).0.so.0.\([0-9]\)000.\([0-9]*\)\|\(.*\)/\1\2\3/g’

The number of 0’s following ‘1’ should match what the real libgtk is: libgtk-x11-2.0.so.0.1000.8

Running locate libgtk-x11 gave

/usr/lib/libgtk-x11-2.0.so.0
/usr/lib/libgtk-x11-2.0.so
/usr/lib/libgtk-x11-2.0.la
/usr/lib/libgtk-x11-2.0.a
/usr/lib/libgtk-x11-2.0.so.0.1105.0
so I removed the 0 on line 421 (not 418) to make it echo $mfile| sed 's/libgtk-x11-\([0-9]*\).0.so.0.\([0-9]*\).\([0-9]*\)\|\(.*\)/\1\2\3/g'
I still don’t understand exactly why it works (the above function would be returning 211050, but it does, and that’s all that matters.

Now to report it on Medibuntu…