Ubaldo was definitely being touted as an ace at the time of his trade.
http://espn.go.com/mlb/story/_/id/6...ez-confirms-trade-cleveland-indians-prospects
First sentence: "In the middle of a surprising season, the Cleveland Indians are getting an ace rather than trading one away."
Being touted as one and actually being one are two different things. Besides that one year with the Rockies what has he done to be considered an ace?