Can't locate/connect both R4.6.7 and R6.0

Hi:

I have two Domino Notes Server on the two Network but I already cross-cert between R4.6.7 and R6.0 and then use R6 server send mail to R4.6.7 server discovered that show error as below:

R6.0 and R4.6.7 console error:

"Error connecting to server SERVER NAME:

your address book does not contain any cross certifications capable of authenticating the server."

“Router: No message transfered to SERVER NAME via notes: your address book does not contain any cross certifications capable of authenticating the server.”

“Router: Unable to open amilbox file SERVER NAME mail.box your address book does not contain any cross certification capable of athenticating the server.”

Camus