Power Beam Bicycle Light - Broken after 1 hour of use

5x Led Light Power Beam Bike Light I've bought two, this one has stopped working correctly just after 1 hour of use. - The batteries are new; - I've checked the contacts, everything looks ok; - If I shake, nothing changes. Update: 3/11/2011 - The seller sent me a new one. I'm using it for the last month and still working fine, but looks like the battery ends faster now. Works for 5h and need a full charge.