ED, as overclocked_enthusiasm has mentioned, a positive gross profit margin indicates that the business segment is contributing to overall corporate profits, even though other segments might be relatively more profitable.
MSFT did not pay anything 'without compensation'. It paid for $40 million worth of chipsets that NVDA had already shipped under the pricing terms of their contract. Since it was decided to go to arbitration, NVDA did not report that revenue in its books until the dispute was settled in case they lost and had to reimburse part of the money. So it's just a matter of NVDA delaying the recognition of that revenue in its financials, nothing more.
By the way, the NVDA annual report I linked to was for fiscal 2003, whereas NVDA had already completed fiscal 2004. Xbox revenue accounted for a smaller percentage (15%) of total revenue for 2004.
Edit: ED, noticed your comment about the profit margin - I won't disagree that we don't know how a 25% gross profit margin impacts the company's profitability objectives overall. However, those were the terms (and anticipated margins) that NVDA agreed to when it signed the deal. I disagree that they changed the pricing on Xbox chipsets. Not a single source has reported so.