Salem

So I have tried to research these problems and have tried various fixes but it they all still occur, sometimes.

Firstly my system is:
Win 7 64bit
ATI Radeon HD 3800 (driver version 8.97 AMD 29/04/2013(up-to-date))
4gb RAM
LAN connection with router
Java 7

I get these errors with both Latikai's version of Enders client and the default client:
Computer freezes when Teleporting to/from Boston, walking around (get loading screen), and simply logging in. Basically any time the client needs to load the terrain.

Also, I get occasional auto log outs and can't log back in because I am already logged in.

I don't have any logs to provide as the computer completely locks up. I have turned java debug logging on but I'm not sure where it actually creates the log.

This really looks like something wrong with your connection.

Thats sort of what I thought too which is why I have a Ethernet cable running through my house, I had assumed it was my wifi being annoying. Turns out 15m is only just enough, I've managed to set it up so it is just above head height.

Also, why would my connection cause my whole system to lock up, wouldn't it just take ages for it load?