LATER CORRECTION: 192.168.0.1
IE9 does instantly.
FF6 immediately and repeatedly re-shows the login dialog.
It is reaching the router because it is displaying the login. But the authorization process is failing. Yet not with IE--so the router is not just failing to authenticate--except with authorization request coming from FF.
I have tried this MANY times tonight in each browser. Same result every single time.
IE9 immediately opens the admin page of the router after name/pwd entered.
FF6 fails every single time.
How/what/why is FF6 preventing this?
I hate IE and avoid it as much as possible, but FF is letting me down badly on this one.