OK, everything there looks good, thanks.
So since the 11th, you have manually updated the definitions from the MSE/Update window, right?
Just so you know, MSE updates definitions 2-3 times per day, and Windows Update only checks for updates once per day (as far as i know).
Today, do NOT run the update from the MSE/Update window.
Go to the Windows Update screen and check for updates.
You may have to do this every few hours until a new definition update is available.
When you see a new definition update is available, try to install it from WU.
If you do not see a new definition available within a day, or the update errors out post back with that info.
If you want to test this quicker, you should be able to uninstall your last Definition Update.
If that is uninstalled, you should see an update available for that definition after you uninstall it...
Hope this makes sense!