ARRGH! Unicode vs non-Unicode again!

I have a very strange problem with a 2008 r2 SSIS package or maybe it's Oracle. I have 3 Oracle 11g databases: PRD, TST, DEV. I am only extracting data. The dba for Oracle just reloaded DEV with a copy of PRD. When my dataflow source is connected to PRD and my dataflow destination is connected to SQL 2008 r2, everyone is happy and there are no errors. However when the dataflow source is connected to DEV and my dataflow destination is connected to the same SQL 2008 r2, I get ye old "cannot convert between unicode and non-unicode string data types". I have set the advanced property ValidateExternalMetadata to false on both the source and destination components and that did not make any difference. Has anyone experienced this or know what it could be on the Oracle side? Or some secret SSIS Global thing? Thanks! Maggie