Black screen after minimizing

[ooger]

Hey all,
I know this has probably been brought forward in the past, but it's lasted over a calendar year so I thought I would bug someone about it.

I'm running windows 8.1 64 bit and every time the graal client gets minimized and I bring it back up the client window is completely black. There is nothing I can do to fix this issue other than restarting the client, which can get annoying after accidentally minimizing the screen a few times.

pls fixo rito unixomado