main menu adding spacing

Hi,

when I click a link in the main menu, there is “phantom” spacing being added before the end of each link, which makes my menu break down into two rows. The spacing doesn’t show in CSS.
When I refresh the page, the spacing is gone and the menu looks good.
Does anyone know why this might be happening? I tried removing padding in CSS, but it doesn’t help.

Here’s a screenshot: http://jelena-art.com/scrn.jpg

As far as I’ve seen, this only happens in Chrome (on Windows).