This was a known issue that we fixed:
Date: Monday, April 02, 2012 9:19:21 AM
Message:
2736753 SQL Table generator component datatype doesn't update to include new columns even after multiple adjust definitions and recompiles.
This may/may not be in one of our rollups. Which version of WF are you using? If there's a need, you can contact Support and get it pushed down to the appropriate rollup version.