Hi,
the same problem when trying the svn version 1241.
please don't use the trunk for batman-adv as it has a serious bug that requires fixing.
Adding interface: ath0 Can't activate module: the primary interface is not active
I think this message gives you a pretty good idea of what the problem might be. I guess your interface ath0 is not up & running. Try an "ifconfig ath0 up". :-)
Regards, Marek