Repros in Chrome 22.214.171.124 and Safari 4 beta.
Does NOT repro in SF 3, Chrome 1, FF2-3, IE7.
Test case: http://uwtools.com/sf4cache/bug.html
1. On load, bug.html appends "js.php" as a script element.
2. js.php issues redirect to public.php:
Cache-Control: no-cache, no-store, must-revalidate, max-age=0
3. public.php contains a js file with headers:
Last-Modified: Mon, 23 Mar 2009 22:26:16 GMT
Reloading bug.html should reload js.php due to the no-cache headers of js.php (e.g., to get a new redirect location).
Reloading bug.html does not load js.php.
I doubt that this is a WebKit issue, although the fact that it fails in both Chrome in Safari suggests that it might be.