> MaObjectSerializationSecurityViolation signal: Serializations beyond 10 
> megabytes are not allowed.

What does your FHKC834Header>>addMember: do?  My guess is it is still building
the entire linked list in one giant commit.  This is not allowed.

Put a Transcript>>show: in your commit-loop; you are expecting to see a bunch
of small-commits right?  I'll bet you will not see any because it's doing it
all in one.

Try opening the debugger and then select "Full Stack".  You will see the frames
where it is traversing your object graph; I'll bet you see a ton in those
FHKC834Members even though you were only expecting one.

Try cutting the file down to just a few members and use your same script.  Then
see if it succeeds in one commit (which would presumably be less than 10-meg).

If you don't get anywhere, send me your script and file and I'll run it..

 - Chris