Diana - drunk or clumsy?

There was much commentary after Diana Ross's appearance on American Idol last week with regards to her condition - was she drunk, or just plain clumsy? I personally didn't think too much about it at the time, but was suprprised at the deterioration of her performance abilities. I am surprised that she is releasing a new album and willing to perform on stage these days. Does she not watch herself on tape? Interesting choice Idol.