VMRC disconnected issue

Hi

When I try to open a vApp within vCloud Director and use the VMRC to view the virtual machine the VMRC only shows a black screen (the options along the top i.e full console, etc are disabled).  It says "connected" then after 10 or so seconds it says "disconnected".

Within Public Addresses I have setup the vCD Proxy, etc.  I think it may be a certificate issue but I reissued a new certificate and have the same issue.

Any ideas?

Thanks.