http://bugs.winehq.org/show_bug.cgi?id=29586
--- Comment #2 from Henri Verbeet hverbeet@gmail.com 2012-01-10 14:48:09 CST --- (In reply to comment #0)
fixme:d3d_surface:surface_convert_format Cannot find a conversion function from format WINED3DFMT_B8G8R8A8_UNORM to WINED3DFMT_DXT5.
That's probably related.