Hi again jodano,
I was looking in the wrong place. I did post the solution to this problem quite a while ago, but that post had since been archived off and I couldn't remember how to do it.
Open the System Preferences. Click on the Dashbard & Exposé icon. Where it says Desktop: and shows F11 as the default choice on the drop down menu, change it to something else. If you click and hold the menu, you can press the Command, Option, Control and Shift keys. You can hold down one or any combination of them. So you can make that Exposé function Command
OptionF11.
The big plus is that changing it kills the Shift+F11 slow motion effect. Then you'll get the keystroke back for Quark since Exposé will no longer be getting in its way.