2 users - 1 group

[Jeff]

I've been scratching my head all day for this:
I have 2 users and 3 shares.
2 shares must be read/write for both while 1 share is strictly private. No
read or write for the 2nd user.
Everytime user 1 writes to a shared folder, user 2 can't delete or access
it.
I've tried creating a samba group for both users, but that doesn't seem to
help.

Any ideas would be greatly appreciated.