This should not occur anymore since the Q++ version of April 24, 2002.
To determine the version information that you are currently using, use the Help/System Information menu to display the system information dialog. The version information is located on the About tab of that dialog. If you are not using the version of April 24, 2002, or later of Q++, then you should download and apply a more recent update.
If your version of QuarkXPress is more recent than April 24, 2002, then you should create a clean copy of all the GridTemplates used in the script that generated this output file, and use these copies from now on.