Binding MOUSE3 on a Razer Mamba 4G 2012

Hi, I'm using probably the de factor standard for a modern wireless gaming mouse, so it's disappointing that there are bind issues with it.

The problem is that when I click the near thumb button (Razer calls it MOUSE4, BF4 thinks it's MOUSE3), BF4 will detect that I've pressed it (calling it MOUSE3) but when I use it in game, nothing happens.  I tried with the VOIP push to talk function.  If I use the far thumb button, which Razer calls MOUSE5, BF4 calls it MOUSE4 and lets that work.  But it's not ideal.

So, now I am using the razer software to reassign that button to '\', which I have assigned as the VOIP push to talk.  I expect that will work, about to try it..