Re: White square?

Hi all, I use D3D8 and I''ve got this weird problem. At the moment, I''m doing a cross-fade between two textures as my "intro" and goes through all 256 alpha values, cross fading in the middle 128, where the two overlap. It takes about 3.18 seconds to complete the cross fade (giving a FPS of about 80 I believe), but the problem is sometimes (though not always) a white square suddenly "appears" on the screen, for no apparent reason. I''ve tried everything to make it disappear, including removing depth/stencil buffers, and disabling win messages. I doubt it''s Windows, because whether or not I have open or closed applications, the white square more or less appears in the same place, not quite to the top of the screen, and not quite to the bottom. The only way I''ve got it to reduce is to use COPY_VSYNC instead of my normal FLIP swap effect Any ideas as to what''s causing this? Cheers, -TF Also, is there any sure-fire way to tell (using a program) whether I''m running debug or retail builds of the runtimes? I''ve tried using D3DSWAPEFFECT_DISCARD, but I don''t seem to get any random noise (as the manual suggests on my back buffer), and when I "flip", I get my front buffer intact. Is this normal? I think so, because although D3D does not guarentee it will be the same, it doesn''t guarentee it won''t be the same, if you see what I mean. I will be grateful of any clarification