Could be several reasons.
- older Sky+ boxes dont support anytime. Only PVR3 type.
- its turned off in the menus
- it takes a few days for it to populate the anytime programmes once its activated
- you turn the box off completely overnight rather than leaving it in standby
- you are being too impatient and think anytime tv is an additional channel rather than additional content
Remember you will only be able to watch anytime programmes delivered to your level of subscription. If you only have the 6 mix dont expect to be able to watch movies...