This may or may not pose a problem visually in the output, as this overflow is sometimes caused by the last end-of-line character.
There is a bug in QuarkXPress versions 8 and 9 which can cause the appearance of spurious text overflow messages. If you are getting text overflow messages that are obviously incorrect then there are 3 different workarounds:
•Remove runaround from objects that are in the same XY position of the left page as the object generating the spurious text overflow message on the right page (or even easier, remove runaround from all objects as this is rarely needed and is often the source of problems).
•Use the Remove Runaround Diary Generation Option.
•Use the Break links to Master Pages generation option.
This bug in the treatment of runaround in master pages is fixed in QuarkXPress version 10.