Did you try to install offending certificate in the list of trusted sources for the account under which the program is running?
mmc -a
... add a component to the mmc to handle certificates
... etc.
I had to do this a few months ago to be able to access a wiki running in a private vm. I remember that the CA which signed the certificate had to be in the list of trusted authorities, too (and that could be true for all CAs up in the chain, eventually).