Here's my setup;
NFS server is running Ubuntu Server using nfs-kernel-server.
The client is running on Mac OS X Snow Leopard. I am mounting using Finder's connect to server.
It will connect fine and show me a file listing. I can create, edit and delete files here. However, subdirectories of that gives me an error if I try to save a file, finder does not give me the option to create directories.
Finder tells me that my user has read & write access, my group has read only access to all the files, even the ones I cannot edit.