Multibox+Proxy=Dropped connection?

[shensu]

Hey everyone!

I recently got into multiboxing in WoW, and have been having a great time. I've been running into a problem recently, though. I'm using a system wide SOCKS5 proxy to reduce lag on my clients. This worked amazingly well the first week. Lately, I notice when I connect =>2 clients, my SSH tunnel freezes. When I traceroute the issue, it's definitely on my end as the 3rd hop always times out, and tracerouting from the ssh shell back to me has a whole bunch of timed out hops the closer it gets to me. It's also weird because I have a second proxy that works fine with no issues. This leads me to believe my ISP is blacklisting the proxy that has the best latency to the server. :(

Has anyone ever had their ISP blacklist their proxy for gaming or accidentally? Would Win7's firewall potentially be causing this? How would I be able to tell if it's the ISP or some other issue? Once again, it's only when I'm trying to play with =>2 clients, so it's fairly annoying.

Thanks in advance!

[zenga]

Is it a proxy that you maintain yourself or a commercial one? If the latter it's possible they restrict the amount of connections you can have to 1 server/ip (could be for example that they noticed the first week that you had multiple clients up through their proxy, and they limited that afterwards).

[shensu]

Is it a proxy that you maintain yourself or a commercial one? If the latter it's possible they restrict the amount of connections you can have to 1 server/ip (could be for example that they noticed the first week that you had multiple clients up through their proxy, and they limited that afterwards).
I maintain my own VPS's, so they're private proxies, in theory.