Has anyone else had trouble with the newer Source water packs? The design is great, but since March 2011 I've had 3, all of which have sprung a leak within a few uses, leaving me looking like I've wet myself and without a useful bit of kit. My retailer has replaced them and sent them back to supplier, but I have now chosen a Platypus. Interestingly, my 4 or 5 year old Source 1 litre bag, which is regularly used in my day pack, continues to give good service.