A connection could not be made with report server at https://webse

Hi,
My report server and report manager was working fine till yesterday. But
suddenly today when i tried to deploy a report i got error: "A connection
could not be made with report server at https://webserver1/ReportServer "
So when i tried to browse the report manager from IIS, I get error:"Could
not establish trust relationship with remote server."
I think its someting to do with SSL. Please help me with that 'czo out of
the blue today I have started getting this error.
--
pmudLook in the event log at the server machine for SSL errors.
Regards,
Martin