Just upgrade the firmware of the TEW-210APB!I have the same problem. We have JAHT and TrendNet TEW-210APB wireless access point working as clients. They cannot connect to MT 512 using version 2.9.8.
Other APs, like Pheenet, SmartBridges or TrendNET TEW-410APB+ connects and works fine.
The difference i've noticed between these APs, that pheenets and smartbridges hides PC mac-address. I think it is called proxy ARP.
Any suggestions?