I don't know if this is what is going on with you, but I was experiencing something similar. A few days ago, in my checkout section, I stated that ebay no longer allowed checks and money orders. I was getting a similar error. It wouldn't let me post. So, I contacted ebay through live chat and they informed me that because my checkout section mentioned the words checks and money orders, ebay wouldn't post it. So, watch the wording on your checkout. Now I've got "Ebay no longer accepts paper payment. Therefore, all I can accept is Paypal" This works just fine. Hope this helps someone!