[Linux] No reset board when I send a program.

Hello,

I'm on ubuntu 12.04, and I've a problem : when I send a program to my arduino board (for instance the test Blink program), the program don't run (I don't see the LED lighting). To run the program I've to press on the reset button or click on "Serial manager", and it's a bit annoying. I tried with several version of the IDE : 1.0 and 1.0.1, but it's the same problem.

How could I reset automatically the board to run the program when I send it to my arduino card ?

Thanks.

What Arduino board and where did you buy it?