I'm using this fragment in a Viewpager contained in a Tab Layout
OK, so there's more code in Tab_Activity which you didn't post? Well, it's hard to tell what's going on without seeing the relevant code bits.
The first thing to try is to call getArguments in the onCreate method rather than the onCreateView method. But that only makes sense if the fragment is actually being used (as opposed to just being created), and the code you posted doesn't show that part.