RandR revisited

Hi,

I have just upgraded my trusty Slackware box to recently released
12.0.  This brings about an upgrade to the X.org 7.1 X server.

Unfortunately, the ion2 module mod_xrandr-2 has stopped working.  I
have debugged the issue as much as I could, and I am afraid I am not
proficient enough in X programming to carry on.

Here's what seems to be going on:
- XRandR registring and so on works.
- Ion (and mod_xrandr) also get the X event notifications for randr
  events.
- However, the call
     FIND_WINDOW_T(rev->root,WScreen) 
  in mod_xrandr.c returns NULL, suggesting that Ion is unable to get a
  hold of a WScreen object that is correlated with rev->root (rev
  being the notification event), if I understand correctly.

What is going wrong here all of a sudden?  Can anybody offer me some
advice as to how to proceed from here?

Thanks in advance,
Toby.
-- 
Expect the worst, it's the least you can do.