Solid Boxes sometimes not working

I recently upgraded my 3d card and I've noticed some odd behaviour with boxes (2d boxes). Before the upgrade there was no problem, but now some of the boxes are see-through. Oddly enough, other boxes using the exact same syntax are filled correctly.

This one works......

Color 0,0,0
Rect 300,200,GraphicsWidth()-600,GraphicsHeight()-560,True
Color 200,200,200
Rect 300,200,GraphicsWidth()-600,GraphicsHeight()-560,False

This one doesn't...... (it's see-through)

Color 0,0,0
Rect 200,200,624,348,True
Color 200,200,200
Rect 200,200,624,348,False

I don't think my gfx card is the problem because I'm using the latest drivers (updated recently). Is this a problem with B3D?

Oh, obviously the 2nd box is just to put a white-border around the black/solid part.

Any ideas on this one? I still can't find a solution to it. Anybody noticed anything similar?

Not sure what you mean. As this is pure 2D, alpha blending can't be involved so I'm not sure what you mean by 'see-through'. Post a screenie?

Well, the 'solid' box basically isn't working at all. The code above is a black solid box, surrounded by a white outline. The white outline works, but the black solid part does nothing, so what I end up with is just the white outline.

The solid boxes do work on other machines though :s

Well, you will get that if you put a black one on a black background. What happens if you change the colour?

Hmm, you're right. I changed it to color 1,1,1 and now it's solid. I guess 0,0,0 is considered a 'mask' colour or something, although it's always worked in the past and still works on other machines when I use 0,0,0. Oh well, 1,1,1 is just as good, thanks for the idea :)