PlayStation Knowledge Center
When launching the PS3 Internet Browser, you may receive a Low Resolution Warning that states "This site works with resolution 720px and above. Please adjust your system settings."
This occurs if the video output from your PS3 is below 720p. This message appears on the initial default website, "http://ps3.us.playstation.com" or others sites that require a higher resolution. You may still use the PS3 Internet Browser to visit other websites.
To avoid this message, you can change the resolution to 720p or above by going to (Settings) > (Display Settings) > [Video Output Settings]. Note that the Composite AV cables (yellow video connector) will not support resolutions higher than 480i, so you will need to change to a different cable.
You can also visit another website that does not require a higher resolution.