I've reported this before, and it has never been resolved. It's been an ongoing problem for about a year now. On occasion - sometimes quite often - click & drag to select text with the mouse will not do anything. The click moves the cursor, but the hold & drag does nothing. I have to close the source file and reopen it to get it to work again. I can leave the solution/project open. I've had this happen with both large and super-small projects (three source files), and only one source file open and with lots of them.
We've seen this happen when you right-click on an underlined comment or string where VA produces a spell-check list that is then dismissed by clicking somewhere else. As AdrianS notes, doing a right-click in the editor fixes the state. This will be fixed in the 1725 build timeframe. case=16204
quote: We've seen this happen when you right-click on an underlined comment or string where VA produces a spell-check list that is then dismissed by clicking somewhere else.
That's very probably what I've done to trigger it. In my case, it's most likely that there was no suggestion at all.