PHP Sessions

Continuing a thread that started in 1.6.1: http://www.couchbase.org/forums/thread/using-membase-php-session-handler

Has anyone found a way to properly expire PHP-based sessions so that membase does not run out of memory?

I have experimented with mbflushctl, and attempted to set min_data_age to 86400, but it does not persist through restart nor does it seem to be cleaning out old keys.

The thread above mentions the solution lying in patching memcached.so.

Any ideas?