Memcache storage failing across mongrels

We've been using memcached to store sessions across our mongrel
cluster but we've noticed that when apache switches us to a different
mongrel our session dies and we get logged out. Further, when I switch
mongrels manually (using different ports) the same thing happens. I've
been hunting around for the last couple of days on this but to no
avail so I thought I would ask the experts.

There are two versions, the version from err's blog and an updated one
that seems like it's more in line with memcache-client 1.3.0 options.
They perform exactly the same.

Also below is a sample dump from memcached -vv

Thanks in advance for any advice!

Chuck Vose