We just got this from Quark.
We’re delighted to let you know about the availability of the free QuarkXPress 9.2.1 update for Mac OS X users. This is an essential update if you are using QuarkXPress 9 with Mac OS X Lion.
You can download the update immediately from the Quark Web site or with Quark Update (In your System Preferences).
Please note that this update is for Mac OS X users only. There is no equivalent Windows update. This update has been released specifically to address the disappearing icon issue that was introduced with the 10.7.3 update of Mac OS X Lion. QuarkXPress 9 is the only version of QuarkXPress that has been certified to run on Mac OS X Lion.