Error loading data to warehouse

Hi,

We are using BODS 4.0

and loading the data from SQL server to Staging then to warehouse and finally to BW target.

On running a full load the data arrived at staging are but giver an error while loading to warehouse area.

error message : cannot insert duplicate key row in object "##" with unique index 

this error refer to the target table of warehouse.

please suggect what could be the resion for the error and where to check for the same.

Thanks,

Rishabh