Anybody try charging your Atrix HD while the phone is off? I will shut my phone off and plug it in. For some reason every time I charge it with the phone off, it turns on by itself as soon as I connect it. I have to connect it first and then shut it down.
Are you sure your turning your phone off?
If you hold the power button for 3 to 5 seconds, it gives you the option to turn the power to the phone off. Otherwise your just basicaly putting the phone in a kind of sleep mode ( short power button push). If you power your phone off, just the Motorola logo, then the charging logo will show on the screen, then it will go off altoghether.
Hope this makes sense.
I had the same problem as well, as it turns out, my phone only does this when plugged into my computers, not when plugged into a wall outlet. I find this very annoying, (and strange) but nonetheless, you can charge your phone when it's off. Hopefully your work and home have an abundance of outlets.