Hi
If machine is noisy on spin, and if you feel any rumble when you turn the drum by hand then most likely it is a bearing failure which is throwing the drum off centre and causing the belt to move. If you think it is bearing failure then your best route to repair would be to take advantage of your Hotpoint 5 year parts cover. For £90 callout you will get a complete tub and drum replacement. More detail would be useful for a fuller answer.
Neil
October 2007