IPSec and x509 Certificates

Hi, Has anybody got IPSec working with X509 certificates? In particular I am trying to connect to a Linux FreeSwan server and the client is running MacOSX 10.2.2. The log message I get from racoon says that it cannot get the the private key: oakley.c:1532:oakley_getsign(): failed to get private key Does anybody have any ideas?? Thanks ttyl Dima