What would cause a visitor to return to the top of the previous page, instead of to the point in the page where the link resides?

Question

I've seen this weird behavior on several sites recently: I scroll down a page and follow a link to another page. When I click the Back button and return, I am left back at the top of the previous page, not at the link. This is very annoying if I'm clicking on links in a search results page or a list of "10 Best Foo Bars...".

See this page as an example. Strangely, the page works as expected in IE6 on WinXP, but not on FF2 on the same machine. On Mac OS X 10.4 it works in FF2, but not in FF3. I checked for any weird preference settings, but I can't find any that are different.

Any idea what is causing this?

Answer 1

Many sites have a text box (for searching the site, or something) that is set to automatically take focus when the page loads (using javascript or something). In many browsers, the page will jump to that text box when it gets focus.

It really is very annoying :(

Answer 2

Typically this behaviour is caused by the browser cache set by the site having a small or no time before expiry.

On many sites, when you hit "back" you get brought back to the link you hit, as your browser is pulling the page from your cache. If this cache has not been set, a new page request is made, and the browser treats it as fresh content.

On the page linked above, the "Expires" header seems to be set to less than a minute ahead of my local clock, which is causing my browser to get a fresh copy when I hit "back" after that expiry time.