I purchased a pc lite led about a month ago. It has 4 dives on it. I am having a problem, the lite works fine before a dive. However, when you get to around 80' for any time it stops working. It has done this to me on my last two dives. When I surface, it is working again. Dive conditions, 37 to 50 degree water. No water found in lite after either dive. Could there be a pressure issue with the led assembly? Help!!