PWR/L/TX/RX just stay on....?

My arduino board seems to have a mind of it's own. Sometimes, literally about 25% of the time, there's no problems. Then i'll connect the board and 4 lights just stay on, the power, L and TX/RX.

I'll be using it one moment fine, then it will just stop working and all those lights come on. Then randomly it might decided to work again.

Anyone know what this means?

no worries, i used a different USB cable and got no problems at all.

dunno why the cable decided to stop working properly though :S