Fixing one bug frequently introduces another bug somewhere else. The new bug may not be discovered until several months later. Here are some older versions of abcmidi in case you need to revert to an older version.
abcMIDI-2013-06-09.zip
abcMIDI-2013-05-10.zip
abcMIDI-2013-04-30.zip
abcMIDI-2013-04-24.zip
abcMIDI-2013-04-21.zip
abcMIDI-2013-04-17.zip
abcMIDI-2013-03-14.zip
abcMIDI-2013-03-10.zip
abcMIDI-2013-02-26.zip

The latest version of abcMIDI can be found here.

seymour.shlien@crc.ca.