I had the same problem happen with a black-x single drive version. If the unit works as long as the power button is held in like mine was, I just duct taped the power button down, lol! If I needed to turn it off, I just pulled the power plug from the back of the unit. I know it's not the best solution, but unless you have the techical know how to replace the switch, you don't have many options.
Oh, and as stated above, if it's under warranty, RMA it.