I had the same problem with a DB2-source.

Problem is: The datasourche object replace the character that have no match in the codepage with a ? and gives a truncation error.

Solution:

Change with the Advanced Editor the Output Column propertie from RD_FailComponent to RD_IgnoreFaiure.

=> OLE-db Sourche object => Advanced Editor => [Input and Output Properties] => [Output Columns] => Choose the field with truncation error => Change propertie 'TruncationRowDisposition' to RD_IgnoreFaiure.