When I was building my PC, at the point when I was plugging everything into the Q connector, I realised there was no slot for a power LED, so I put it into the HDD led.
Now, the front light is flashing, like a HDD Led would. It's a bit annoying, is there a way to get it to stay on? ;c
I wouldn't advise unplugging it as, a hard drive activity light that is perpetually lit, especially when the computer isn't otherwise responsive, is often times a sign that the computer or device is locked up or "frozen" and should be restarted manually.
In other words, as many people have already said its meant to be like that.