This is actually what I think might be a flaw in the programming for the UBB forum software. They use HTTP POST as opposed to HTTP GET. Of course, in Internet Explorer, when you hit the back button, it doesn't resubmit the HTTP POST. When you use Firefox, it will give you the option of resubmitting the POST. It would be a better idea to use a HTTP GET, which resubmits the information in the following manner.
http://www.randomsite.com/search.php?name=namehere
You can also look up into your address bar to see an example of a GET with a number of variables. In a POST command, the variables aren't carried along...