Kernel panic with high network traffic and USB storage

[Polichronucci]

I am reopening a closed topic because I still have problems solving this. My Pi Model B revision 2 runs on 4.95-5.05 Volts with just Ethernet cable and an external powered USB Hub. I log in via ssh and there is no X server. I use kernel 3.6.11-17-ARCH+, the latest. My problem is the same as other people had in the past, kernel panics after high network traffic. Running software are tor server, rtorrent(in a tmux session), nfs (rpc.mountd,rpc.idmap,rpcbind), ntpd, pdnsd, sshd, and a script <<bash -c "while true ; do echo 3 > /proc/sys/vm/drop_caches ; sleep 1 ; done &">> which is surposed to help with kernel panic but sometimes fails and the only thing it really does is to leave the Pi hanging for a minute or so and then networking starts very low till it get to 900KBps and hangs again. Is there a solution I missed, how can this be fixed?

Thanks is advance,
Nick