I have 3 linksys wrt54 flashed with openwrt 7.09, webif'ed and installed BATMAN 0.2-rv478.1, all OK I think.
not sure what web interface you installed but are you aware of the fact that revision 478 is more than 2 years old ? Your current problem seems unrelated to batman but if you experience trouble / bugs with batman it might be wise to upgrade to the latest stable release.
From the ssh prompt on .3 I can ping .2 with no loss and ping .1 with ~ 6% loss. However, if I try to ping .1 from the pc connected on the ethernet port of .3 I get no route to host. Putting wireshark on the ethernet ifc shows the arp going out but nothing coming back. Interestingly enough if I ssh into .3 and ping .1, with wireshark running on the ethernet of .3 Is see the outgoing ICMP but not the reply (which is there because the ping succeeds) . It seems as if the local host traffic is not truly bridged.
You bridged the LAN & WLAN on every device but the devices are not bridged with each other, hence you mix bridges & routing.
What IP address did you assign to your PC ? Does your PC have a route towards the .1 (probably not) ? You also have make sure that all nodes have a route towards your PC. You can achieve that using HNA. See: http://www.open-mesh.net/wiki/AnnouncingNetworks for a detailed explanation.