NT/Mac network access privileges problem

Last resort hope someone can help!!
Network has an NT Server 4 and
OSX servers. The NT Server
authenticates all users on the
network. My problem is the privileges
for PC Windows 95/98 users, all PC
users cannot save changes on the
NT Server, although privileges say
they can, but if the same user logs
onto the NT Server with a Mac
computer they are able to make the
changes. It also works the other way,
if a Mac user logs on using a PC they
are unable to make changes. I have
had help from others with NT
experience but nothing they tried
seems to work.