A quick nugget… If you get this error:
[DTS.Pipeline] Error: component “OLE DB Source” (79) failed the pre-execute phase and returned error code 0xC0010001
Check that your variables are mapped and that they can be read at run time. Similarly if you get the same error code with the description:
Configuration from a parent variable “XXXXX” did not occur because there was no parent variable. Error code: 0xC0010001.
Check that you have spelt and referenced the correct parent variable.