When you examine permissions, a local group from a trusted domain has permissions on a trusting domain, but access is denied.

Local group permissions from one domain have no effect on permissions in another domain. If a users only permissions to an object in a trusting domain come from their membership in a trusted domain's local group, they do have have permission in the trusting domain.

If SCOPY from the Resource kit is used to copy from the trusted to the trusting domain, remove local group permissions before using SCOPY /O.