Indenting paragraphs manually

[Dani Moncayo]

Hi!

I'm looking for a simple way of indenting paragraphs manually (in text
modes), and I've just read this node of the Emacs Manual: (info "(emacs)
Indentation"). It explains, among other things, the general behavior of
the <TAB> key in text modes:

      In text modes, <TAB> inserts some combination of space and tab
   characters to advance point to the next tab stop (*note Tab Stops).
   If the region is active and spans multiple lines, it advances the first
   character of each of those lines to the next tab stop (*note Using
   Region).  [...]


I'm used to that behavior in other editors, and I like it, but
is not what I currently see in Emacs. e.g.:
 - Start Emacs (emacs -Q)
 - Set text-mode in the *scratch* buffer. (text-mode).
 - Set transient-mark-mode on. (transient-mark-mode 1).
 - Select the first 3 lines.
 - Type <TAB>

What I was expecting:
 - The selected lines move to the next tab-stop.
 - The region remains active, so that I can repeat the indentation
several times in a row.

What I see:
 - The selected lines are not not moved at all.
 - The region is deactivated.

Please, could someone explain this? Am I missing something?  (I guess I
am, and that's why I'm posting to help-gnu-emacs instead of
bug-gnu-emacs)

TIA

---
Dani Moncayo

In GNU Emacs 24.0.50.1 (x86_64-unknown-linux-gnu, GTK+ Version 2.22.0)
 of 2011-02-26 on dani-P5PL2
Windowing system distributor `The X.Org Foundation', version 11.0.10900000