Errors With Demo Phonebook

I have installed the Yii Framework and the demos.

I ran the Yii Requirement Checker page, and it came back with everything listed as "passed," with the exception of the database extensions that I am not using. (SQLite and MySQL ARE installed and are listed as "passed" on the Yii requirements check page.)

However, after I enter the "demo" login user and password to log into the phone book demo, I get a box that displays the errors "Data communication error" and "http request error."

Can someone give me some advice on what I might try to remedy the problem?

Thank you!