I thought Rollup8 for SP1 was supposed to be fixing this in part, so there would be no need to report on the problem?
The named properties debacle is a very sore subject. As admins have no control over x-headers coming into their organisation, their exchange databases have been ticking time bombs.
This needs fixed properly and thoroughly documented ASAP. Seriously. There has still been no advice about what to do if folk have been experiencing the problem post rollup 8. There is a reluctance to keep updating the named properties quota knowing that there is a catastrophic failure on the horizon. (having to constantly create new databases and migrate thousands of users is a catastrophe).