Mark,
SSD doesn't pay for the first 5 months of the disability. I guess they consider it a probation period. They determinded that I became disabled in Dec. 05. So dec to april are not payed. they started in May. But as I didn't apply till sept. they gave me back pay from May to Dec, when they made the determindation to approve. I know it's not great, but that is the way they do it. I would have them redo the calculation as you are not getting SSI. Have you thought to apply for it? If not, then they shouldn't count that amt.
Mary