Are you replacing with original lamps, from the projector manufacturer?

I've used lamps with packaging that looks identical, including the manufacturer name on the packaging, but based on price, I knew they weren't produced by the projector manufacturer. I would usually get about 1/4 of the rated life out of such lamps.

In my past experience, the only lamps I could count on, were direct from reputable sources, supplying direct from the manufacturer.