David,
StarOptions are returned to your account if you cancel a reservation within 60 days of check-in. However, when returned to your account, the StarOptions are restricted to use for a reservation made within 60 days from check-in.
If the restricted StarOptions are banked, the restriction is removed. The banked StarOptions can be used for anything the StarOptions could have been used for before.
If a reservation is made with banked StarOptions and is later canceled within 60 days of check-in, the banked StarOptions become similarly restricted again.
Once StarOptions are banked, Starwood keeps separate accounts for banked and unbanked StarOptions. I think it is a good idea to use the banked ones first. ... eom