In Opera 9.0 the Right Column Disapears (#main column change width)

Hi, great theme, but in Opera 9.0 when I hover the mouse throught the Navigation Links (in a 3 column layout, with navigation links at the left sidebar), the main column (center) varies its width making the right sidebar disapear, and appearing at the end of the page. I don't know if I'm explaining it ok, because my english sucks :-/
¿Anyone know what could it be?