It's MinecraftServers.net pinging you, I get it too. Turn off enable-query and see if it helps. It's probably not what is crashing you.
http://bgp.he.net/dns/minecraftservers.net#_dns
I saw a lot of ppl couldn't log in after the ICBM update went live.... once I logged out I couldn't come back to any 1.1.3 server either.
Here's the fix: http://forums.technicpack.net/threads/cant-play-voltz-at-all.42549/
enjoy!