Here is the code you need:
If WB.ContainsFocus Then
MsgBox("We have focus, disappearing...")
WB.Document.Body.RemoveFocus()
End If
Now, the question is, when to run that code. If you put it in the WebBrowser1_GotFocus event, you'll need to turn it on and off. Turn the code off if the user is interacting with the WB Control, and turn it back on when they are not and when you expect to be experiencing the problem you've mentioned.
Of course, you could add another line to ensure a particular control/tab/panel etc gets focus after you remove focus from the body. Also, here are 3 other SO questions that have answers which may help you, but these will take you in directions different to the direction I've provided, probably due to the fact that the questions are not identical to yours, but are similar enough to be useful (not listed in order of preference).
Prevent WebBrowser control from stealing focus?
Webbrowser steals focus
Focusing WebBrowser control in a C# application
UPDATE:
I just wanted to add, instead of the .Body.RemoveFocus() you could do this:
WB.Document.Body.Parent.RemoveFocus()
Which I prefer, since the .Document object didn't have an explicit .RemoveFocus method on the intellisense I was gettign in VS2012 RC. This is probably referring to the HTML tag (and not the .Document object) and since the html
tag is the only parent to the body
tag, it makes sense, and there is no "HTML" object directly available in the intellisense under object, since you can get it via other means, so it's just more convenient doing it this way.
Cheers, and let me know if you need more info on anything.