Walther P99 FS Green Gas Pistol airsoft gun

In the first few days of ownership the gun was great. Very accurate, tight groups even at 10 yards. But after shooting about a thousand rounds, the valve that releases gas to propel the BB started leaking. I shoot a round, but gas continues to flow for a few seconds, usually emptying the entire gas supply. The problem exists with both the magazine that came with the pistol, and the spare magazine that I bought. It is very frustrating, and Pyramyd has not been of any help. They do not respond to e-mail, and they even removed the poor review that I left. If you feel lucky, or if you do not intend to shoot much with it, by all means bye it -- it looks great and it feels solid. But if you actually intend to use it for more than a few days, stay away.