MSDN Virtual Labs: "No Connection" message

Hi,

I am facing "No Connection" problem while connecting to labs. I am behind corporate proxy server. Nevertheless I provide all proxy server details in the "No Connection" dialog box. Still I am not able to connect to the labs. Our 443 port is also open. Also our system administrator has tried various options but still problem exists. Can someone please tell what else could be the problem? Thanks in advance.

P.S.: I have already looked at thelinkin this forum. But unfortunately it was not helpful.

[757 byte] By [Mukund] at [2008-2-12]