Crash after password protected screensaver

Hi, If you run a BPlus game in windowed mode (try this one http://www.greyaliengames.com/easterbonus.php) with a screensaver set to "On resume, password protect" it crashes after you enter the password. First I see the desktop drawn in the game window, then when I click the mouse I get a MAV.

Hmm I just made a simple test:

Graphics 800, 600, 32, 2
While Not KeyHit(1)
	Cls
	Text 10,10,"testing..."
	Flip
Wend

and this works, so it must be something more complex in my code. I'll investigate...

OK found out why I was getting a crash. Calling User32 GetCursorPos when the screensaver is showing returns null and my code didn't like that.

Anyway, it no longer crashes but it still shows the desktop on the window until you click it and then the game comes back but the backbuffer (or fontbuffer, I can't tell which) is corrupted.

Is there a way to tell if the screensaver has been showing and the backbuffer is corrupted? If so I could force a redraw. thanks