Oz, steady on mate. I don't think anyone has stated 'or inferred' you have said anything which is false. I think everyone is trying to provide you with a logical reason why you have experienced premature wear on those threads. The only way you can discover what is wrong is to postulate what is likely to be the cause and then exclude the most improbable causes until you are left with the most likely explanation.
It may be though that no definitive explanation is ever found? I myself have suggested galling is the cause. Your own theory(and the dealer's) is that the extra pressure needed to secure the tailcap because of the extra length of the rechargeable batteries is the cause. I suspect that the manufacturer may also be at a loss to also explain the problem unless they have other examples. Unfortunately you have one of those issues with your light that is fortunately very rare. It is obviously very annoying but hopefully it will be resolved by the warranty? Whatever, the result please keep us up to speed?
Doug :)
It may be though that no definitive explanation is ever found? I myself have suggested galling is the cause. Your own theory(and the dealer's) is that the extra pressure needed to secure the tailcap because of the extra length of the rechargeable batteries is the cause. I suspect that the manufacturer may also be at a loss to also explain the problem unless they have other examples. Unfortunately you have one of those issues with your light that is fortunately very rare. It is obviously very annoying but hopefully it will be resolved by the warranty? Whatever, the result please keep us up to speed?
Doug :)