Patch provided by Jacques Beaurain (thanks!) to fix bug #322. I've added

the text below as comment:

adding a glFinish() here is to prevent Geforce in 'full scene antialias' mode
from antialising the Blender window. Officially a swapbuffers does a glFinish
itself, so this feels really like a hack... but it won't harm. (ton)

intern/ghost/intern/GHOST_WindowWin32.cpp

@@ -348,6 +348,10 @@ GHOST_TSuccess GHOST_WindowWin32::setOrder(GHOST_TWindowOrder order)
 
 GHOST_TSuccess GHOST_WindowWin32::swapBuffers()
 {
+	// adding a glFinish() here is to prevent Geforce in 'full scene antialias' mode
+	// from antialising the Blender window. Officially a swapbuffers does a glFinish
+	// itself, so this feels really like a hack... but it won't harm. (ton)
+	glFinish();
 	return ::SwapBuffers(m_hDC) == TRUE ? GHOST_kSuccess : GHOST_kFailure;
 }