Evil Kraig F (3/13/2013)
Most likely they're validating. Turn on Delay Validation.Also, make sure you're using what's become a defacto standard for SSIS called procs:
SET NOCOUNT ON;
SET FMTONLY OFF;
WHILE 1=0
BEGIN
-- Result set for SSIS to use
SELECT
CONVERT(VARCHAR(30), NULL) AS ColumnA,
...
END
... Real code here.
...unless you're using 2012, in which case the result set definition moves to the Execute SQL task.
If you haven't even tried to resolve your issue, please don't expect the hard-working volunteers here to waste their time providing links to answers which you could easily have found yourself.