keystroke interpretation?

I loaded RH9 recently.  Everything was working fine, but some keyboard 
shortcuts were different from RH7.1 which I had previously used.  No 
problem, I went into the "keyboard shortcuts" under preferences in Gnome 
and changed them back to the way I liked them.  But then bad things 
started happening.

1.  CTRL-ALT-DEL no longer brings up the dialog with three options for 
logout/reboot/shutdown.
2.  CTRL-MouseClick no longer opens a tab in Mozilla.  Through hours of 
troubleshooting this seems to be a Gnome problem as it does still work 
in KDE, however CTRL-ALT-DEL no longer brings up the dialog box in KDE 
either.

CTRL-ALT-DEL in both gnome and KDE simply logs me out.

I've used gconf-editor to look at all the keyboard bindings and have 
found nothing.  I sure wish I could figure this out.  CTRL-click is very 
important to me, and I'd like to get it back in Gnome as KDE is annoying 
to me.  Also, I sure would love to understand what happened to 
CTRL-ALT-DEL. 

In general, an understanding of how keyboard input is handled is 
required to solve this problem.

Can anyone help?

Thanks,

JJ

PS - I went through every kind of XKB setting file I could find and 
found nothing to help