Thanks, David. Sorry my search engine fu wasn't up to finding your original conversation (and sorry that I thought I had updated to trunk, but actually only pulled the 4.5 updates.) **
The workaround in the trunk update works for me.
There are some mysteries to this, including the surprise that an Etoys 5.01 image can save class comments fine, without the flush workaround.
Best, David C.
** - I just rewrote the 'update stream' page of the swiki so I don't make the same mistake again. Please check it for errors: http://wiki.squeak.org/squeak/3154