Normal Bug or Not

You follow a link to a forum topic, i.e. this one

http://www.zorpia.com/forum/15/433242

the page says topic doesn't exist (I know for a fact this one doesn't)

you press the go back button (and nothing happens)

Can anyone actually get that button to do something (that it is supposed to) (my config of Firefox 3.6 doesn't)

The script exists

input type="button" name="Button" value="Go Back" onclick="javascript:history.go(-1)" /

I can't see "javascript.history.go" declared in the html