Hi!
samba is uninstallable in unstable, as it depends on libtalloc1:
samba: Depends: libtalloc1 (>= 1.3.0) which is a virtual package.
libwbclient0: Depends: libtalloc1 (>= 1.0.1) which is a virtual package.
A binNMU should fix this.
Thank you!
Best regards,
Nelson