http://bugs.winehq.org/show_bug.cgi?id=9774
--- Comment #22 from Stefan Dösinger stefandoesinger@gmx.at 2007-10-25 15:21:27 --- Hmm, this looks like a precision problem, and the clear background color comes through. This could actually be a game bug, where the game doesn't make sure that the vertices are close enough at each other. So the in princible undefined old colors come through.
Now while Windows doesn't give any guarantees regarding the back buffer content after a present call, it is unlikely to be the color that wine currently clears the back buffer with. On most drivers it is the old front buffer content, or just black. In both cases the lack of precision won't be that visible due to the general color theme of the game. So the question is if it is wine's fault that the old color shows up, or if the old color just shouldn't be such an obvious color.
Can anyone download the directx sdk and install it on a windows box? In this case you get a new control panel entry which allows you to switch to the debug runtime. The debug runtime fills the back buffer after a present with a yellow and black color pattern according to the docs. With this a simmilar bug might be visible on Windows.