msn messanger

I am using a proxy server(proxy+) for accessing internet. I cant use msn messanger.It says “cant connect to server”.
I browse through the net with out any problems, and i use yahoo mesanger too.

I have given the proxy address and port in msn messanger,still i coudn’t connect.

My proxy uses port 1863 for http.
Can any one help.

Thanks in advance.