A bulb 'popped' and went dark and a new bulb doesn't work?

my downstairs light went pop and didn't work again. I changed the bulb but when switched on again doesn't work. The other downstairs lights still work and the switch is still 'on' for the downstairs lights on the circuit breaker/fuse box. First problem in 3 years, never happened before - any suggestions?

Maybe i should add that i've been using energy saving bulbs in these fittings although technically because they are on dimmer switches they don't recommend doing that. however so far so long as i don't dim the lights and keep them at full brightness the lights have worked fine. Not sure if that has contributed.