The issue with 7th gear will remain an issue until Fanatec changes the wheel firmware or games change the way in which they handle gear changes. As of now, the only game that works with 7th gear is GT5 due to the way in which it handles shifting between gears. Forza handles this differently and cannot be made to work properly until the firmware on the wheel is changed.
That said, the CSW can handle 7th gear right now and I have a firmware (as I stated earlier) that I can give folks for that. Please let me know if you would like the firmware Logi and I can send it over.
If you are running into an issue with Dirt 3 but no other games, there is either an issue with the wheel or the game itself. That said, you can try upgrading your firmware to see if it helps. Here is the link for that:
http://www.basherboards.com/SFA1_Firmware/
You likely have one of the earlier versions still...
I should note as this has come up a few times now. The SFA1 simply takes the inputs from a USB shifter and present itself to the wheel as a Fanatec shifter. It does not communicate with the game, only the wheel does that. This means that if you are having issues such as mapping a button properly, or no shifting at all in certain games, this is likely due to some incompatibility between the wheel and the game.
I hope this helps shed some light on the subject.