[jvriezen]

We've had at least two bulbs with the flickering problem. Our theory is it may be one or both of the following (or a combination)

1) Bulb for some reason runs hotter than the others.

2) In a ceiling can light, this can cause the can-light fixtures to overheat protection switch to trigger, causing flickering. The can's trigger might also be more sensitive to other cans. Other factors might be amount of insulation/air space above the fixture in the ceiling/attic.

Note that the bulbs are not recommended for enclosed fixtures where little or no air can circulate.