Buttons Not Displaying Properly

[BQ]

Hopefully someone can help me with this problem.

I have several sites where I have used xara menu-maker. Quite frequently, but not always, when I "mouse over" a button I get a "red x". If I move off the button and then move back over it the button will display properly. The buttons usually display OK when I initially open the page so the links work properly.

Does anyone have a solution to this problem?

BQ