I suspect that some or all of the translator add-ins are not correctly registered.
A quick test is to check in your Add-in manager if the SAT add-in gets loaded when you invoke a SAT import.
I would also try to exit Inventor and restart Inventor or even a reboot to allow for a full registry cycle of the product.
You can also try following steps as explained in this technical solution :
http://usa.autodesk.com/getdoc/id=TS13404176
Bob Van der Donck
Inventor Support Technical lead
Bob Van der Donck
Principal UX designer DMG group