With the progress bar at about 40%, the page hangs and teh cursor turns into a spinning beachball.
Created attachment 28837 [details]
A shark time profile
Build: Version 4 Public Beta (5528.16, r41894)
It'd be worth attaching a version of the page in question in case it changes, perhaps by saving it from Firefox.
Created attachment 28848 [details]
Page source saved from Firefox
Oddly, the problem doesn't seem to manifest itself when read from the source files on disk.
The problem doesn't manifest because none of the style files or JS files load. Adding a <base> element makes it reproduce just fine. I'm going to assign this to myself and try to find a reduction. The problem is caused by layout triggered by getting the offsetWidth property of an element. There is a long section of <div> elements with identical styles. I suspect there is some quadratic (or worse) behaviour being triggered by the style.
Created attachment 28849 [details]
Still has way too much JQuery.
I just tried the last test case, and in WebKit.app Version 4.0.3 (6531.9, r48276) it does not reproduce any more.
Suggest closing this bug.