Comment 2 for bug 411856

The symptom for me was that my mediawiki installation came to a crawl immediately after upgrading to 9.10. The upgrade was a sequence from 8.04, 8.10, 9.04 and I didn't test mediawiki on the intermediate steps, so I am not sure if the upgrade path is implicated, or the karma upgrade itself. It's hard to imagine only a few reports of this issue if it were widespread.

Adjusting /etc/default/memcached to hold
<code>
ENABLE_MEMCACHED=yes
</code>
and restarting memcached seems to be satisfactory