Hi 
Think I know what you're trying to say

When we click to start a scan...
Example - Full Scan
The scan starts .. But the buttons for the other types of scan still remain visible in the same window.
Not Sure!

If we are supposed to be able to do 2 scans at once though

I really like the new look of - Avast 5

However!
I don't think I would ever want to try running 2 different types scan at the same time

And...
I can certainly see how the layout of the scanning window could cause a bit of confusion.
Hally