Great catch, Jerome!
this case should remember as to, always, after release, roll all the plugin versions to current date, so we won't get that problem again (with old stable rolling because of any important reason and conflicting with HEAD upgrade paths).
So yes, +1 to repeat (with current versions) the install/upgrade changes in
MDL-14548, both in 1.9 and HEAD.
About qamaster... crap, I cannot find any reason. Perhaps it was created before the fix? Strange, strange.