Check your configuration and make sure that packet forwarding is enabled on the Ethernet Advanced Page. Also make sure you have clients associated to the AP. If there are no clients associated, then the AP will automatically go into Blocking State. The following is an excerpt from this URL: http://www.cisco.com/univercd/cc/td/doc/product/wireless/airo_350/accsspts/ap350scg/ap350ch3.htm#wp1025620
"The forwarding state displays the port's current forwarding state. The state for normal operation is Forwarding. Four other settings are possible:
UnknownThe state cannot be determined.
DisabledForwarding capabilities are disabled.
BlockingThe port is blocking transmission. Blocking is always displayed when there are no clients associated to the access point.
BrokenThis state reports an Ethernet port failure "