File sharing issue with NT4 work group and 2003 server domain

I am having problems sharing files between NT4 sp6 computers that are on a workgroup and Windows XP pro sp2 that are part of 2003 server domain.

I have setup sharing on the folders and tried to adjust permissions but I still can’t get access. The error is basically telling me I don’t have access but I’ve done everything I can think of to give access to the computers.

The 2 NT4 computers on the workgroup can access the shares but none of the computers on the domain have access. Also 2 laptops running Vista in the same workgroup can’t access the shares either. Any help would be much appreciated!