I think you should be able to strip all the spaces out of that string, like this:
Code:
//tdonnelly@otter/music /mnt/Music smbfs rw,-N,-g0,-u1001
(goes to check man fstab)
(checks google)
hmm, not a lot of information about it.
That said, the default user and group for smb filesystems (and msdos too) is the user and group of the directory entry it is mounted on. This is the way I have always dealt with user:group issues.