I think you need to have a heart-to-heart with your commissioner.
Yahoo.com has Rollins as the 39th ranker player and Jered Weaver is ranked as the 84th best player. See it at http://sports.yahoo.com/fantasy/mlb/new ... on1-top100
ESPN.com has Rollins ranked as the 61st ranked player and Jered Weaver as the 66th best player. See it at http://sports.espn.go.com/fantasy/baseb ... 2k11top300
CBS Sports.com has Rollins ranked as the 42nd ranked player and Jered Weaver as the 36th best player. See it at http://fantasynews.cbssports.com/fantas ... 0-for-2011
These three sources are the most popular sport sites used for fantasy baseball.
I would suggest that you print out these three sets of rankings, quietely pull you commissioner aside, show him the rankings, and politely ask him why he felt the trade of Weaver for Rollins was unfair. If he still upholds his veto, perhaps you might like to ask him to resign as commissioner.