http://bugs.winehq.org/show_bug.cgi?id=14558
--- Comment #23 from Henri Verbeet hverbeet@gmail.com 2009-06-10 17:15:40 --- Created an attachment (id=21728) --> (http://bugs.winehq.org/attachment.cgi?id=21728) hack
This is starting to look like a driver bug. It seems glGetTexImage() doesn't return correct data the first time right after drawing to the texture with an FBO. The attached hack works around this for me, but is obviously not the way to go.