Keyboard tab doesn't do anything on my builds of emacs-25

[Harry Putnam]

Running: Gentoo linux
  GNU Emacs 25.0.50.1 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
  of 2014-12-20 on gv

Pressing the `tab' keyboard key in text-mode (and several others I
tried) does not insert a tab, however checking `lossage' shows: <tab>
[indent-for-tab-command]

Is this normal for emacs-25 (very recent from git repo)?

I'm aware of C-q C-i of course, but wondered if it is possible to
restore the old working of tab key?

Or maybe its a matter of my local keyboard configuration, or other
local env?