RAMPART 1.3 The certificate used to sign the message is not trusted

[Christian Mielke]

Hello!
I have following problem: I call a service and sign the message with my 
certificate. RAMPART on serverside always says that the certificate used to 
sign the message is not trusted. But I looked in my keystore and the 
certificate is trusted. I use PKCS12 keystores. The policy I use is the sample 
3 policy only without the timestamp.
Greetings
Chris