Is there anyone who has experienced problem with the ETS EC sanders (150/3, 150/5 etc)? I purchased one 3 months ago, and after just a few uses, it would act as though the motor was "stalling", sometimes slowing down, other times turning off completely. I'd need to hit the power button to turn it on. Since it was so new, I returned it to the store and they just gave me a new one. I've had the new one for about 2-3 months, used it a few times, and the other day, the exact same thing. Wanted to know if this is something related to how I'm using the sander (i.e. too much pressure) or whether others have experienced this.