Gdk-WARNING: BitBlt failed

[Egon Andersen <post talura dk>]

Hi,

I've seen this warning on MS Windows XP:
Gdk-WARNING **: gdkdrawable-win32.c1568: BitBlt failed: Handlen er ikke 
gyldig.

(The last 4 words translated to english: "The handle is not valid.")

This seems to happen when Windows XP goes into 'Screen-lock'.
There are probably 100 or more occurences of this error message.
The same application compiled on/for Linux do not cause this 
error-message, when Linux goes into 'Screen-lock'.

Do anyone know what causes this problem and knows about a cure?
(There is no timer signals in the application, but perhaps there are 
some internally in Gtk+/Gdk.)

Best regards
Egon Andersen