I have a 24" flourescent light fixture in my kitchen that is probably about ~12 years old. I recently changed the two bulbs from typical kitchen and bath spectrum to daylight spectrum (6500 K color temp).

Now the lights won't fully come on, they light dimly and flicker. If I fiddle with them a bit I can get them to fully illuminate. The fixture has a cover and I've found that if I leave the cover off, I can get the daylight spectrum lights to operate normally. If I put the cover back on, they won't function properly. I can't find any interference or shorts.

Does anyone have any advice on this? The daylight bulbs operte at a higher color temperature, but both sets of bulbs are rated at 20 Watts. I'd hate to have to replace the fixture if it's not necessary.

Thanks in advance.