Comment # 9 on bug 1101393 from Stefan Seyfried

I reproduced the issue.

The problem is, that xscreensaver (our default in XFCE) by default has the
feature "fade to black on activation" with a fade time of 3 seconds.

So what is happening is:

* suspend is triggered
* xfce4-power-manager calls xflock4
* xflock4 calls xscreensaver-command -lock

While this is happening, suspend continues.
Suspend is fast, after resume, xscresensaver is still fading to black and
locking the screen.

Not sure how to fix that, other than unconfiguring the "fade to black" thing in
xscreensaver.

Maurizio: please try to reproduce after disabling the fade-to-black option in
xscreensaver preferences.

(I never noticed this, because I use i3lock-xlock-compat instead of
xscreensaver)