broadcom problem

[G.]

My mini 10 Dell as a Broadcom 43x driver.  It has been working great.
All of a sudden I can not connect to the various routers within reach
until I logged in as a different user.  I had been playing with
special effects/compiz and the computer crashed twice and then this
problem occurred.

I can not do sudo as" 'guest' is not in the sudoers file."

Any suggestions?

thanks

gary