Mark,
Does the leak stink of gear oil or motor oil? Distinct differences... as there is no mistaking gear oil. It stinks. Is the pan wet with oil above the disconnect? Since you cleaned it... check it later... if its leaking again then smell it. Yes, the front diff can leak on its inner seal... which is the seal the intermediate shaft uses as the shaft passes through the pan over to the disconnect. But I would think that the leak would just pass straight down and you would see it more pronounced on the driver side than over on the passenger (disconnect) side. There is no seal for the differential or disconnect to the pan itself. Each just fits into its respective pan opening as they are bolted in place.
Bill