Double check your SSID. If you follow the instructions exactly, you'll set the SSID the router is broadcasting to one ID, and the SSID the bridge looks for as another ID (in your case one will be "frc877" and the other will be just "877"). This could be your problem, you need the SSID on each side to match exactly.
For more info check the presentation FRC 41 gave with FRC 522 here:
www.team41robotics.com (on the home page) and here:
www.robowizards.com (under "News and Announcements")
-Jeff Erickson, FRC 41