Forget the other folks. First run a ping plot for about 10 minutes. Then send that plot to Skuzz. He'll be glad to look into that and see where your problem lies.
Just assuming it is HT is jumping the gun. There are several hops between you and their servers. Your connection might be traveling through a server or servers that are lagging a bit.
Every player you talk about discoing could have a totally different problem or they might all be on comcast. Comcast is a known issue affecting many but not all folks.