jaruj9, with your error;
"No device on /dev/ttyACM0"
can you go into your command line, say in terminal and list your devices by typing;
ls /dev
to check if ttyACM0 does in fact exist?
If the operating system doesn't list the port, then it will fail to upload.
Unplug the cable to the Arduino, wait 5 seconds, plug it back in and do that command again and see if you can see it or any other new tty port since you pluged it back in.
Yes, this plugin by Jantje is wonderful, I wouldn't use Arduino's now if I wasn't able to use the Eclipse IDE.
Paul