Slightly off-topic, but I am hoping for a bit of help here in judging the scope of this.
When running McAfee EPM 2.1 on a 10.9 system, when we attempt to run an manual update to the virus definitions we are seeing an error saying that an "update is already running". This doesn't happen all of the time, but enough for us to be concerned. Having a hard time nailing down the cause, as it isn't 100% reproducible. McAfee is blaming our configs rather than the product, so I wanted to see if anybody else was seeing something odd with their McAfee installs.