A year or 2 ago we though we had this very issue licked. The other night, out of the blue, our Oracle --> SQL Server job stops working with this "Cannot acquire connection from connection manager" error. What worked for us was to set DelayValidation = True for all datapump tasks sourced by Oracle and to redeploy the package. Our SQL environment is Win 2003 Server on an i64 using the Oracle 9.2 client tools to pull from a number of Oracle boxes on 10.2.0.3.0 of the DB.

Ken