Map Graphics going wonky?

I started to see some jacked up graphics yesterday, especially in Act 5 when looking at the world map. Anyone else been having this issue or is it just me? I loaded the world map and it was very blocky, not as in pixelated but squares all over, then after a few seconds they disappeared.

On PC but this happens virtually every time I go to Act 1 thru 6.

Last for a few secs until the high res vesion kicks in.