Ebay has changed the way they track affiliate transactions which is how all rewards sites connect with them. This means that Ebay will drop from some sites either temporarily until they change their tracking internally or permanently if the new ebay system (rover) isn't compatible with the rewards program.

There have also been a few tracking outages with Ebay so many programs will take them offline when notified of an outage to avoid the headache of trying to get manual claims etc processed. It may be a while until it is bedded down.