Microsoft Visual Studio is cannot shut down as a modal dialog is active

I have encountered this error message several times when working with Reporting Services designer.

"Microsoft Visual Studio is cannot shut down as a modal dialog is active"

All of the sudden the IDE doesn't seem to respond to keyboard inputs anymore, and when you try to shut down Visual Studio, you recieve the error message above.
The error states that a modal dialog is active, but it is, however, nowhere to be found.

I found this feedback post at MSDN and apparently it is an active error (16-8-2006), which unfortunately also means that no hotfix is available at this time.

Googling the error returns multiple results, so I guess it's a widespread bug.

Anyway, the taskmanager seems to do the trick of closing down VS, even though it's not a nice solution.