Macbook Pro will not work as a wifi hot spot when connected to ethernet

I have a brand new Macbook Pro (version 10.8.2) and am having problems using my computer as a hot spot. When I connect my computer to an ethernet connection, I go to:

1. Settings

2. Sharing

3. Internet Sharing (It is not checked)

4. Select "Share connection from ethernet"

5. Select "to computers using Wi-fi"

6. Select "Wi-Fi option"

7. For security I choose "WPA2 Personal" and it prompts me to create a password

However, when I create a password, the "OK" button is greyed out and I am unable to select it. Can anyone help? Thanks!