I was setting up my recently replaced SB when the sound volume suddenly dropped off, which used to happen with my original SB. Eventually, the volume returned, as it always did on my original SB, but why is this happening again, on a brand new machine. Just like it did on the old one? I tried rebooting but that didn't reset the volume. Then I tried pulling the power cable off the machine, which disengages the docking station and the input to the external speakers. When I plugged it back in the volume returned to normal, but dropped off again soon after. Every time I disconnected to power and plugged it back in the volume returned to normal, for a short while before dropping off again. Clearly, there is a connection, but what is it? Is there an overheating issue? Because when I put the machine to sleep and return later the sounds stay up for a long time, hours actually before it drops off again.