>What I would like to know is if I may have a problem with the >D300s or if I have something set incorrectly? is this just a >known difference between the D300 and D300s?
Yes, the implementation of Auto ISO & flash changed on the D300s and subsequent cameras. The camera seems to use Auto ISO to try & get a 'correct' ambient exposure before adding flash, rather than keeping the ISO low and adding more flash to get a good exposure. I don't think many people like the newer implementation, even though (for TTL-BL) it might be argued to be more 'correct'.