Yea I can explain...
When Google spiders the billions of websites it uses many of its servers to cache the changes on the many web masters sites... There are many servers doing the spider ing work; such might pick up the websites a bit differently from another of its own...
When you check Googles info for your site(s) you are checking one or so of its "datacenters" which may or may not be up to date with its other "datacenters"... There for it is very possible to get conflicting data when checking on your site(s)...
As far as I understand it this is accurate ... Drop a line to Google as they are very helpful so if you have any questions... do yourself a favor and read their online documentation... this will help you out a lot...
Hopes this helps you out...
Later,
.