Clear your dns, we moved servers (I think).
Open a command prompt (Start->Run->cmd) and type in the following:
ipconfig /flushdns
[EDIT] To explain futher:
If you accessed BC through that proxy for the first time, then that proxy will have gotten the correct, new, ip from his dns, while your computer is currently still holding on to the old address because it's cache says it hasn't expired yet. Which is why you need to flush it.