Bulb life not as stated. Failed after 6 months of occasional use.

This projector is use occassionally for presentations in my training class. After 6 1/2 months of use including only about 50 hours of use, the bulb failed. My other projector is still going on its original bulb after 4 years. Called Infocus tech support and was told a lie so bad that I had to have him repeat it for verification. I was told, "A bulb will wear out faster if it isn't used. If you want it to last the longest you should turn it on and use it every day." Still waiting for them to tell me if they will replace the bulb since it failed 1 week out of it's six month warranty.