When scrolling on a website I've built, using the CSS property
position: fixed works as expected to keep a navigation bar at the very top of the page.
In Chrome, however, if you use the links in the navigation bar it sometimes disappears. Usually, the item you've clicked on is still visible, but not always. Sometimes the entire thing disappears. Moving the mouse around brings back part of the element, and scrolling with the scroll wheel or arrow keys just one click brings the element back. You can see it happening (intermitently) on http://nikeplusphp.org - you might have to click on a few of the navigation the links a few times to see it happen.
I've also tried playing with the z-index and the visibility/display type but with no luck.
Is this a known issue or is there a fix to keep fixed elements visible?
Only effects elements that have
top: 0;, I tried
bottom: 0; and that works as expected.