I can see why people are upset with Foulke. But really, it's not been as bad as people think. Look at today - bloop infield single, intentional walk, unintentional walk, and in the end he gives up a run to a great hitting team after the bases were loaded with no outs. He hasn't pitched since Sunday. He's still got the goods, he just needs a groove.
Give Foulke, Renteria and Millar some time for God's sake. The division isn't won in the first half of the season.