This is a world of warcraft armory page. You can pass the cursor over a gear slot (around the edges of the inventory) and a tooltip like window pops up showing you the item. In Firefox, the tooltip always shows under the mouse. In Webkit (523, 525), if the window is scrolled to 0,0, it works fine. If you make the window say 1100 pixels tall and scroll so only the bottom gear items can be seen (wrists, weapons) and pass the cursor over, the popups show offscreen, off the top. I am not JS aware enough to determine if this is a script issue, or a webkit issue, but it works ok in Firefox 2
Note: WoW is very popular and the WoW armory gets millions of hits, so if you see "Loading..." for the tooltip, you may need to try later, as Blizzard does not have enough server capacity for this popular feature.
This sounds like the page is still using a Safari 2 work-around for Safari 3. It needs a reduction, though. Confirmed with a local debug build of WebKit r29451 with Safari 3.0.4 (523.12.2) on Mac OS X 10.4.11 (8S165).
Looks like this page doesn't exist anymore, & this was a Safari 2 bug. Closing, please reopen with a new url if this bug still reoccurs on a different page!