I had same problem a few times months ago... Suppot will not help. I finally found out what was happening. Ebay will kick out your listing if it violates any percieved rule. It's automated and is WRONG all the time. Other than the obvious, a banned item, you need to read closely for any banned words: I had a german war relic get API'ed for the word NAZI? I also had a mispelled word which could be construed as a cuss word. But most likely, it's the problem I had that took forever to figure out... Payment methods: Acepting Cash in your listing description? I guess ebay doesn't like cash, they don't get their high fee's!
Hope that helps?
-R