I too used a carbide lamp for many years, both spelunking and SAR - a wonderful technology since you were carrying both light and fire starter in one package (except when you were on the scene of a plane wreck - carbide was then rather inappropriate). I always carried spare felts, jets, sparkers, and rubber washers and I was occasionally glad I did.

I would second Ireckon - can you give an example? I have bought lights at the local big boxes - fortunately for relatively noncritical uses. I will stick with my Fenix models for absolute reliability. I recently rendered first aid to a fellow worker with grand mal seizures. It was a fairly dark environment and my Fenix, available on my key ring, was absolutely critical, especially for checking pupillary response. It has lit every time with great reliability, and due to its variable lighting levels, I am confident I could hike all night with it if necessary. And since it is a keyring light, it goes fine in any work environment.