A multi-thread BUG of Openssl?

[Fred]

I'm using openssl to build a multi-thread server. The enviroment is WinNT + VC+ openssl .95a. the server make client-verify. My problem is: when 2 client tried to connect to the server at the same time, there is always one client which will be reject. The Server returns X509_V_ERR_CERT_SIGNATURE_FAILURE. But when these 2 client connect to the server one by one, there is no problem. They can connect to the server without problem. I have added a X509_V_ERR_CERT_SIGNATURE_FAILURE- handler in the verify-callback function like this:  case X509_V_ERR_CERT_SIGNATURE_FAILURE:     ok = 1;   break; With this change the two client can connect to the server at the same time.   I think it is a multithread-bug of Openssl. Any one has the same expirence?   Zhang