issue when using Funnel Stage

[dsxdev]

Hi
I three Datasets from which I am reading data , Dataset A, Dataset B and Dataset C.
I am generating a Dummy Column.
These three datasets have output to three Column Generators which generate the Dummy column value as 1, 2 and 3 for rows coming from Datasets A,B and C respectively.
Records from these three datasets are input to a Funnel.

Data from the Datasets is coming fine and output of each column generator is fine but when the data comes out of the Funnel Stage some columns coming from the third Dataset C are becoming Null in Char columns and 0 for Integer columns.
All these columns are nullable.

Can any body tell me what could be the reason?

These columns were added to the Datasets recently prior to adding these columns the job worked fine. These columns were added to all the three Datasets.

Any input would be helpful.

Regards