Does Emacs have a power-saving mode?

[Lars Ingebrigtsen]

The past few weeks I've been noticing that, on my laptop, if Emacs isn't
displayed on the screen (complete hidden by other windows, for instance,
or iconified), then after a while my erc connection times out, and my
Emacs-based music player stops playing.

If I reveal the Emacs window, the music starts up again and erc
auto-reconnects.

So it kinda seems like...  sentinels and process filters stop firing or
something?

Does this sound familiar to anybody?  And if so, how do I stop Emacs
from behaving like this?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no