sealeopard,
you're right, it must be a permissions problem, because the script accesses shares on a Server in the AD Domain. The NTFS permissons on the W2K Fileserver in the old NT4 Domain are set to full access to NT4 domain\Domain Admins, read to everyone and read to AD Domain\Domain Computers. Share permissions are set to everyone full control. The NT4 Domain is fully trusted to the AD Domain.
Are there any other permissions i have to set to that share, so that the machine logon script could access the share?
I thought its enough to permit the AD Domain\Domain Cumputers, but this is not working.