WordPress itself is not resetting connections normally (at least I have not experienced it so far), so the connection gets shut down by one of those: a) the webserver, b) a http firewall, c) an IDS, d) a tcp/ip firewall or just by e) network hardware.
As you can reproduce the problem, you might want to contact IPOWER and while they real-time montior the network connection and server infrastructure you can trigger the error again. The networks and servers administrators should be able to find the real cause of your problem.
In case you request does not even reach the server, you might have some application running inside/alongside chrome / firefox that is forcing the connection to reset on the client side.
As far as you’re concerned to fix it on your end, take a browser that is not having the problem.
An additional question: After getting that connection reset message, are you actually logged out from the blog or not? If not, this is a sign for the client/server problem. If yes, then probably WordPress is triggering this. But I suspect some network problem in combination with HTTP headers send by those two browsers, but it’s hard to say with the information you provided.