Steps:
1) using sharepoint 2010 designer workflow, create an instance of a Document Set and have the ID of the created instance returned.
2) set the returned ID to a field in the list that was used to initiate the workflow.
3) look at the id of the value returned, vs the actual id of the document set instance.
result: the returned value is -1 of the actual value.
expected: the same id values.
i tried to "get around" this by adding a calculation step to add 1 to the value returned.
what it did was add 1 to the end of the string value returned (so if the wrongid was 322 and i expected 323 to be the final calculated number, it returns 3221).