This should be done before the calls to 'AddObject'. In my case, this reduced the time a piece of code took to process 2,000 records from 8 minutes down to about 10 seconds.
This fix requires more research to determine if there are side-effects to setting these. If this is a shared context, then the flags should be set back to their original values after 'SaveChanges' has been called.
Note that this only works with DBContext,and not ObjectContext