This is a known issue and will be corrected eventually. The delay in the starting of scans is also an issue that originally was by design so as not to overtax your system when it's in use for other processes, however the newest versions override that as they are less resource hungry anyway. Eventually that too will disappear. Some people are late getting the most recent versions because they obtain their McAfee software from a 3rd party, such as their ISP or PC Maker etc., and that can mean late arrival of fixes due to those 3rd parties sitting on newer versions. That's something that McAfee can't control unfortunately.
My contact at McAfee is following up on this issue. The last we heard on an update coming in the middle of a scan or vice versa was 'it can't happen' and of course we said, 'oh yes it can'. To be continued...... ;-)
The delayed scan issue has been dealt with and when you get that particular version it should disappear.