NullReferenceException - PrimeOutput Error

I got an error in SSIS package that is reading data from DB2/AS400 into SQL Server 2005 x64. All rows from the source table were moved to the target table, but DataReader Source still failed:

[DataReader Source VALNREQ [1]] Error: System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.SqlServer.Dts.Pipeline.DataReaderSourceAdapter.PrimeOutput(Int32 outputs, Int32[] outputIDs, PipelineBuffer[] buffers) at Microsoft.SqlServer.Dts.Pipeline.ManagedComponentHost.HostPrimeOutput(IDTSManagedComponentWrapper90 wrapper, Int32 outputs, Int32[] outputIDs, IDTSBuffer90[] buffers, IntPtr ppBufferWirePacket)

[DTS.Pipeline] Error: The PrimeOutput method on component "DataReader Source F57005" (1) returned error code 0x80004003. The component returned a failure code when the pipeline engine called PrimeOutput(). The meaning of the failure code is defined by the component, but the error is fatal and the pipeline stopped executing.

After a while I realized that a column has been added to the source table. I refreshed the DataReader Source and directed new column to target and finally everything was working.

It would be short sighted to blame Microsoft for this error. I was using select * from table in DataReader Source. I changed it to the current a list of columns and I hope that my package will not fail if someone adds column to the source.