I have two groups of 4 recessed lights in my kitchen (eight lights total). Each group is on a three-way circuit (i.e. can turn the group on/off from two different locations). The bulbs are Ecosmart 60W CFLs. They are on a 15A 120V circuit with no other loads on it (circuit has a few outlets that aren't being used). The breaker for the circuit has never tripped as far as I know.
The problem I have is that most of the bulbs eventually turn off. I've heard them make buzzing sounds when I turn on the light and sometimes they flicker. But eventually they all seem to turn off. I've unscrewed and re-screwed them in and they again will flicker as I jiggle it around but once completely seated it turns off. I've replaced all the bulbs. Right now only 1 of the 8 bulbs is on yet they are all new bulbs. I've checked each recessed lighting receptacle with my voltage pen and they are all getting voltage. I'll add that the lighting cans/canisters in the attic are mostly covered/surrounded by insulation (if that matters or makes a difference).
Does anyone have any idea why this might be happening or what else I can check? Could it be the wiring of the receptacles in the attic? Perhaps the bulbs are just bad bulbs for these type of receptacle?