Do you rinse between the iodophor and the Starsan? Neither needs to be rinsed or causes an off-flavor, but I wonder if the you are not rinsing between the two, if the two chemicals are causing some kind of reaction?
The other issue and "sour" being the key is an infection, possibly a lactobacillus bug? You may want to replace all tubing you use and soak everything else in bleach. When you made the strawberry wheat did you use real strawberries? If so, maybe picked up an infection from them?
Member of the Metro South Homebrew League (Mash-Holes) - Weymouth, MA
Primary - Empty
Kegged - Surly Bender Clone, Winter Warmer Stout
Bottled - Nothing