Firstly, yes, there's a fix - see the man page extract:

cifs.show_snapshot By default this option is FALSE. The snapshot directory ~snapshot is no longer shown at the root of a share. This is a change in behavior from previous versions. Setting this to TRUE will restore the old behavior. On Windows NT 4 or Windows 95 clients, the user can access snapshots by entering \filer\share.snapshot (or ~snapshot or ~snapsht) in the Start->Run menu. Snapshots can also be accessed lower in the share by providing a path to a lower directory. Snapshots can be accessed through DOS on any system by changing to the ~snapsht directory.

We changed the default due to problems with NT backup software handling snapshots badly.

We use NFS and CIFS on our toasters. Since upgrading to 5.1.2, our PC clients no longer see the ~snapshot directories. (This is the .snapshot directory on unix clients.)

Is there a fix? This is disconcerting. Or should I say broken?