https://bugs.winehq.org/show_bug.cgi?id=37398
--- Comment #17 from Stefan Dösinger stefandoesinger@gmx.at --- I am writing this from memory, so please bear with me...
Afair converting P8->RGB on blit is wrong, and we have a test showing that. The real problem here is that a surface isn't marked lost correctly here on a mode change. The application should recreate it or restore it to give it a RGB16 color format instead of P8.
Henri recently made improvements to handling of lost surfaces in ddraw. Maybe it's easier to handle this now.