SSAS 2005: Errors in the OLAP storage engine: The sort order specified for distinct count records is incorrect.

Hit this error during a Analysis Services 2000 - 2005 conversion project. Did some research on the error, and there's not much in the way of documentation here. Fix turned out to be that 2005 does not handle NULL values in the int column that the distinct count measure is built from. Best solution to this is to filter that data out in the data source view.