You should be able to but you probably won't want to revert back to your current firmware anyway as it's so old, the purpose of the updates are to fix any problems people are finding while running older versions. If you have problems with the update then what you might need to do is install each update between your current (V3.1.1) and the most up-to-date (V3.4.4) step by step, rather than jumping straight up to the latest. See how you get on with jumping straight to V3.4.4 though as I suspect this won't be an issue and will fix things.