Conversion error calling conversion routine

[say2prabhu1]

We have different versions in dev,production.The job is running fine in 7.5.1.While running the same job in 7.5.2, we are getting the error "Conversion error calling conversion routine timestamp_from_string data may have been lost".
But the same job is running fine in 7.5.1 for different scenarios.
Right now i don't have access for 7.5.2.

I am reading the records from oracle DB.For date column, i am reading as timestamp.I have used NVL in oracle stage.I think this is creating problem in 7.5.2.

Please suggest your opinion.
Why it is differing?Datastage is responding the same job in different manner in 7.5.1. and 7.5.2