ANSWER:

Are you sure that you have in fact managed to insert wlan0 (the one that connects to the existing AP) into the bridge? Because the problem is, this is simply not possible. Running brctl show should confirm that the bridging did not succeed. (the link says it’s not possible to bridge wireless client interfaces to wired interfaces, but it’s true for bridging to any interface, including wireless AP interfaces)

The alternative is to make the “repeater” act as a NAT router. However this has the usual problems that NAT brings (e.g. need for port forwarding, inability to discover hosts on the other side). The link provided explains how to set up NAT.

by Ambroz Bizjak from http://superuser.com/questions/418252