- the archive links are remade, even though they exist (probably not a big deal)
- config.db.tmp is written, and then .db becomes .last and .tmp becomes .db.
Thanks for reporting, I think the change I just checked into CVS should fix this (admin.py was calling MailList.SetUserOption() without the keyword argument "save_list=0", causing the list to be Save()d at least
admin_user_chunksize * len(("hide", "nomail", "ack", "notmetoo", "plain"))
times(!) every time the list's Membership Management page was visited).
Probably batching up all the "changes" into one config.db write is a big big win.
The bigger a admin_user_chunksize you're using, the bigger this win will be :)