Hi,
In such a meshbox, I installed OpenWRT Kamikaze 8.09. In order to do that, I downloaded the OpenWRT trunk and all the available packages from the OpenWRT repository. Then, I built the image selecting all the interesting packages; among these packages, in the network section, I selected batmand (B.A.T.M.A.N. 3 routing daemon). By the way, I did not compile batman by myself but it was directly integrated in the Kamikaze image.
I downloaded the OpenWRT trunk and compiled the i386 image before loading it into a qemu environment. I can confirm that batman does nothing if started without a debug level. It seems the main thread is not doing anything. Interestingly, if I compile & run batman on my debian machine it runs without problems. I guess OpenWRT uses some different libs / compile time options / etc that provoke that problem.
As a short term workaround I suggest you start batman with a debug level and redirect the output: batmand -d 3 wlan0 > /dev/null 2>&1
I will try to debug this during the coming days but can't promise anything as I'm looking for the needle in the haystack.
Regards, Marek