I have read that Ovi Store only allows you to download a file once, being on the initial purchase.
Is there a way to backup the individual sis file rather than just doing a general backup?
I must say I generally avoid games downloaded direct to the phone since I invariably manage to lose the game the next time I do a firmware upgrade. This is particularly bearing in mind the general advice after such a upgrade is to reinstall programs rather than carry out a backup restore.
If not, it would seem the best advice is to always purchase from anywhere but Ovi Store. Handango for example.