As previously stated i have reecnetly acquired the stiga vila classic,albeit 2nd hand,and it too kept throwing the mower drive belt. Furthermore it was shredding the 'v-belt' into pieces. I have since spoken to 'belt specialists' and they say the problem is the v-belt itself. With the tensioning pulley forcing the back of the belt it is doing something the belt isnt designed for. SO they have suggested,and i have tried with great success,The 'Gates powerated belt No6858 12.5/13mm x 1475'. It states it is 'stronger-than-steel-reinforcement.For mowers,tractors,snow blowers and appliances'. I am aware it isnt a 'stiga' belt SO PLEASE check that using the above belt wont go against any warranty cover you may have. I have the manuals for the mower and will photocopy them and send them to anyone who has suffered the same problems.It is also illustrates how to change the belts etc.
Rick Holly
August 2008