It could either of the following things:
Old versions of the SMH software, then try to update and compare versions.
Firewall between the servers or firewalls on the destination servers.
Sim can use 3 certificates, 1024, 2048 or 4096 bits, some versions of SMH only accept the 1024 (older) versions.
What is the error on the failing trust job and is your repair account on the target servers?
i believe port 445 is used for repairs, so also look for that.
