SuSE 9.2 slow https connection set up

I was running a server with SuSE 9.1, providing various things, including webmail for a few friends. All was working well. I've just set up a new server with SuSE 9.2, and now some clients are finding https connections take several minutes to connect to it. As far as I know, the configuration of the new server matches the old. Its as though the connection isn't made until something times out, but I don't know what to monitor. I tried logging DNS queries, and I can't see anything suspicious there. Any suggestions? Be great to sort this out. Cheers, Paul.