Violet LED short half-life?

When scientists first started getting violet light out of an LED in the laboratory, they were plagued with a major problem: short device lifetimes. Apparently this problem has yet to be konquererd. Several violet LED installations I made in "the early days" (January & February of this year) are already failing; the LEDs in them are at or below half their original intensity. Usage has averaged probably 2-3 hours daily during this period. None of the other LEDs in the installation have dimmed.

Only one violet LED has retained anywhere near its original intensity (the one in my computer case), and as far as I can determine, it is being well underdriven.

Has anybody else had their normally driven to overdriven violet LEDs begin to poop out on them after a few hundred hours or so?

I have a pretty good test underway right now, so I'll be able to report back after a month or so. I have some violet LEDS in a couple of night lights, so they see many hours of use per day. It'll be pretty obvious when they dim, since I can barely make them out now!

Bummer since purple is my wife's favorite color.