Heard about this this morning, didn't realise it was yours. I thought it was the crank pulley bolt not tightened/torqued properly from the conversation I had. Not uncommon for a charger install to highlight this when it's been "fine" upto that point. There's actually 2 published tightening torques/angles in the renault workshop manual, and I believe most of the time these have slipped the looser way has been used. I always use the tighter of the 2 settings, and I've not had any of the cars I've done a cambelt on that have subsequently had a charger fitted slip the pulley. There's an arguement for adding the megane sprocket to reduce the risk, but there's definitely an error in the manual too
Just to make it clear I hold Ktec in no way responsible as they have done everything they can to help me out. I appreciate that these things can happened having owned many modified cars in the past and was just after peoples opinions as were I stood. Now that every one knows the full story they may be able to advise me better.
As for having the bolt torque to correct level or a level specified by myself, this was done before I had the charger so would have expected it to be done to normal specifications, and as Dan as said he has not experienced any problems with the belt when a charger has been fitted when the bolt has been torqued to the correct level.
Especially when it's their own fault.