Home screen is 720p instead of 1080p

Whenever I switch on WDTV Live, I always see my home screen to be 1080p. It will display in my sony tv. After playing to make WDTV live work for my USB wireless dongle, I see my home screen to be 720p. Have I done something wrong. How to get back the 1080p screen back?

In my case I have sometimes experience the opposite. First 720p and later I get 1080p.

I have also found that my HDMI settings sometime changes from 1080p to 720p. Do not use automatic settings.

Check your HDMI settings and choose what your TV manage…

Regards