Task Manager failing to close apps?

I'm in my first week of playing with my AA1L and like it a lot so far. But I have had two occasions to ctrl-alt-del to use the Task Manager to kill apps. And in both cases it hasn't worked.

The first time around a file manager window had gone irritatingly blank; TM said it was sleeping, but couldn't kill it. I just went on with my work and shut the One down as normal, no problem.

The second time was worse - Media Player had a nervous breakdown when playing something from a USB pen (I'd booted with this attached I think, if that makes a difference). Not only wouldn't the app die, but when I tried to shutdown the One it refused. A monocrhrome unpopulated version of the desktop stayed on the screen. Task Manager would still come up, but that was all the machine would do. Everything was fine when the machine eventually lost and I reconnected it to the charger and re-booted.

Any comments? Any stronger forms of re-boot available to me?

 

A mixture of the bad and good this time: I just had another file manager window jam, but I did manage to zap it. No usb pen involved this time, just a machine left on for a while. The jammed file manager seemed to prevent others from opening.

So far I'm impressed with the Acer's hardware, but no much with Linpuss. Ubuntu may be in the near future of my Acer.