Canon 5D Mark II- Monitor turning off

Is anyone else have trouble with the monitor turning off after you take a picture. My monitor sometime will turn off after I take a picture. When it turns off I can't get anything on the monitor. I can wait a few minutes or turn the camera off and then I can view things on the monitor. At first I thought that I was doing something wrong. It does't turn off everytime, just once in a while.

Any help would be appreciated.