It's backwards compatible so no worries.
All the 1.0, 2.0, 3.0 non sense means is you can get higher speeds out of that slot
For example in the future, when we have amazingly fast graphics cards, 2.0 slots will slow them down since it can't process all that data at once.
You have nothing to worry about though, we haven't really even broken the 2.0 speeds yet. 2.1 and 3.0 boards are just getting us ready for the future and they're all completely backwards compatible.
So your 9800 GT will be fine