We recommend you to provide further information (be as specific as possible) about the issues you are getting. This way, other forum users will be able to help you with accurate information. Is the Slingbox hardwired to the router? What's the Operating System of your computer? Are you running the Setup at slingbox.com?
If the issue persists and you are not able to run the setup using the Web Based Player at slingbox.com I recommend to reset the plugin and also try a different web browser.