Cavalier don't sound very p2p-friendly. Have a read of this article, sounds like they're using a traffic management system. There's also a statement in there saying that they're deploying several blocking rules to deny access to sites or applications
Light Reading - IP & Convergence - Cavalier Uses Procera - Telecom News Wire

You could try changing ports. In LW tools > options > advanced > firewall config. Change LW's listening port to 64049, or something in the range of 49152 - 65535. No guarantees that this'll help, but it's worth a try.

Your Java's a bit old, try installing this version. Use the JRE offline installer & remove your current Java version before you install this one.
Java SE Downloads - Previous Release - JDK 5

Your router has an internal firewall. If you do manage to connect, you could look at port forwarding for that router. I can't find specific instructions for your router, but the instructions below might help...they're for another Buffalo model but you might find they're good for your router as well. Or there might be info about port forwarding in the router's manual.
Port Forwarding for the Buffalo WHR-HP-G54

Good luck