http://bugs.winehq.org/show_bug.cgi?id=17296
--- Comment #87 from Juan Lang juan_lang@yahoo.com 2011-06-03 14:17:14 CDT --- Thanks for that log. This part of the log looks relevant: trace:secur32:schan_CheckCreds dwFlags = 00000018
In particular, the SCH_CRED_MANUAL_CRED_VALIDATION flag is set. This is supposed to prevent schannel from validating the certificate chain, and should probably imply that gnutls should be instructed not to validate it, either.