Hi John
I noticed in your post that mozsupport has been updated recently so downloaded a copy.
The only update in the package for those with mozsupport-2016-03-16.zip installed is the fntcnf1.dll file.
However, for the sake of "completeness" I unzipped all files from mozsupport-2016-04-29.zip overwriting existing files.
Seamonkey then would not start - Sorry, that is incorrect as it appears in the Process List and can be "killed"; it does not appear onscreen and the cpu meters are peaking.
As I had been running Seamonkey merely minutes earlier I guessed the problem may be related to the mozsupport update.
I "backlevelled" fntcnf1.dll to the version from mozsupport-2016-03-16.zip and no problems - I am posting using Seamonkey.
The older mozsupport may still be available here
http://os2news.warpstock.org/mozsupport-2016-03-16.zip if you want to give it a try.
Regards
Pete