Why are the browser buttons gone?
Depending on how you got to the site, the standard browser buttons may be gone. The forward, back, refresh, and stop functions have no consistent meaning for a multi-frame application like the map server. Using the buttons causes the application to fail so they were removed. If they are present, you should not use them nor should you use key stroke combinations for the same purposes. If you get locked up and need to refresh the site use Ctrl-F5.