This may be unrelated, but some NFS clients have problems using the .snapshot way of accessing snapshots. Apparently, Netapp returns the same NFS filehandle or at least the same inode number for snapshots as for the current version of the file, and this can confuse NFS clients.
Can you say more about the clients that are getting confused? (What vendor, what OS, etc.)
We do *NOT* return the same file handle for snapshotted files, and the clients we've tested with have worked just fine. (We do return the same inode number, since we didn't want to reduce the number of available inodes by 5 bits that would be required to uniquify accross all snapshots.)
If some clients are having trouble handling the snapshots, then we need to have a talk with some implementors...
Dave