You can recreate this in any browser. It's because data/input is not being sanitized/checked properly.

I forgot where the errors came from, but the originated at: http://www.collabrr.com/statistics.php. Try this string: ?user='

Go back and check those files/lines and make sure there are no blank lines or ";" being left out. I can't really tell you much about the problem without seeing the code. Hope that helps!