Storage File contains multiple Packages

Job running DTS package converted from SQL 2000 to SQL 2005 failed with the following error:

DTSRun: Loading... Error: -2147220438 (8004042A); Provider Error: 0 (0)
Error string: The specified Storage File contains multiple Packages; Loading requires a Name or Guid.
Error source: Microsoft Data Transformation Services (DTS) Package
Help file: sqldts80.hlp
Help context: 713

Solution that worked for me was to open the DTS package and then save it. (Click Package/Save).