Safari won't minimize.
After I watch a youtube video in fullscreen I press esc to exit fullscreen and the yellow minimize button turns to grey as the image shown below and it wont let me minimize the safari window this is the only application that I have this problem in. How can I fix this?
MacBook Pro, OS X Mountain Lion (10.8.5), i7(2.9Ghz), 8GB Ram, 750 GB, 13in