https://bugs.winehq.org/show_bug.cgi?id=37424
--- Comment #16 from Stefan Dösinger stefan@codeweavers.com --- Created attachment 49974 --> https://bugs.winehq.org/attachment.cgi?id=49974 wined3d: Update fragment program constants when switching from arb ffp draws.
Can you give this patch a try? It fixes the corners on the login screen for me.