I encountered this bug recently. Compiling a new version of that module from http://ftp.samba.org/pub/unpacked/samba_3_next/source3/modules/vfs_shadow_copy2.c worked better for me, in that shadow copies would appear in the Previous Versions list
I patched the code enough to handle an absolute snapdir, but I also use a basedir in my config, so using the linked version was necessary for me.
