On a daily basis, the webring checks each site on each ring for the navigation code. When you join a ring, you have to tell the ring where you are placing the ring navigation code (the next, previous, all, random etc. buttons).
Each day the ring checks to make sure that the code is where you told them it would be. A red thumbs down means that the ring does not see the code where it should be, and therefore considers that site to have broken the ring.
You have your navigation code in a frame side bar. Is that where it was when you joined the ring? The best thing is to go log into the ring, and use its ring checker. Or just manually update the location of the code.
That will get you back to a green thumbs up
-Alan