Serial monitor disconnecting itself Problem: can't print to the serial monitor, it appears that the serial monitor disconnects itself after uploading a program.

I'm brand new to arduino, and I'm trying to upload a basic program to print to the serial monitor.

I use an arduino uno and my OS is Ubuntu.
I am connecting the arduino to my PC via USB.
Using Arduino Studio Release 0.0.5 experimental build 0.0.5-16058

(I am able to communicate via the digital output pins, tested by making a simple circuit to make the led light blink)

Here is the program:

void setup()
{
    Serial.begin(9600);
}

void loop()
{
    Serial.print("test");
    delay(500);
}


Here is the result of the build, look at the last line and it says the serial monitor was disconnected? Why would this happen automatically?

[2/2/2016 8:51:26 PM] - Start Building
[2/2/2016 8:51:26 PM] - CPP File Created [/tmp/build1454471486915/test.cpp]
[2/2/2016 8:51:26 PM] - test.cpp compiled
[2/2/2016 8:51:26 PM] - CDC.cpp compiled
[2/2/2016 8:51:27 PM] - HID.cpp compiled
[2/2/2016 8:51:27 PM] - HardwareSerial.cpp compiled
[2/2/2016 8:51:27 PM] - HardwareSerial0.cpp compiled
[2/2/2016 8:51:27 PM] - HardwareSerial1.cpp compiled
[2/2/2016 8:51:27 PM] - HardwareSerial2.cpp compiled
[2/2/2016 8:51:27 PM] - HardwareSerial3.cpp compiled
[2/2/2016 8:51:27 PM] - IPAddress.cpp compiled
[2/2/2016 8:51:27 PM] - Print.cpp compiled
[2/2/2016 8:51:27 PM] - Stream.cpp compiled
[2/2/2016 8:51:27 PM] - Tone.cpp compiled
[2/2/2016 8:51:27 PM] - USBCore.cpp compiled
[2/2/2016 8:51:27 PM] - WInterrupts.c compiled
[2/2/2016 8:51:27 PM] - WMath.cpp compiled
[2/2/2016 8:51:27 PM] - WString.cpp compiled
[2/2/2016 8:51:27 PM] - abi.cpp compiled
[2/2/2016 8:51:27 PM] - hooks.c compiled
[2/2/2016 8:51:27 PM] - main.cpp compiled
[2/2/2016 8:51:27 PM] - new.cpp compiled
[2/2/2016 8:51:28 PM] - wiring.c compiled
[2/2/2016 8:51:28 PM] - wiring_analog.c compiled
[2/2/2016 8:51:28 PM] - wiring_digital.c compiled
[2/2/2016 8:51:28 PM] - wiring_pulse.c compiled
[2/2/2016 8:51:28 PM] - wiring_shift.c compiled
[2/2/2016 8:51:28 PM] - CDC.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - HID.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - HardwareSerial.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - HardwareSerial0.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - HardwareSerial1.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - HardwareSerial2.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - HardwareSerial3.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - IPAddress.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - Print.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - Stream.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - Tone.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - USBCore.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - WInterrupts.c.o linked to core.a
[2/2/2016 8:51:28 PM] - WMath.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - WString.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - abi.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - hooks.c.o linked to core.a
[2/2/2016 8:51:28 PM] - main.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - new.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - test.cpp.o linked to core.a
[2/2/2016 8:51:28 PM] - test.ino linked to core.a
[2/2/2016 8:51:28 PM] - wiring.c.o linked to core.a
[2/2/2016 8:51:28 PM] - wiring_analog.c.o linked to core.a
[2/2/2016 8:51:28 PM] - wiring_digital.c.o linked to core.a
[2/2/2016 8:51:28 PM] - wiring_pulse.c.o linked to core.a
[2/2/2016 8:51:28 PM] - wiring_shift.c.o linked to core.a
[2/2/2016 8:51:28 PM] - test.cpp.elf linked to core.a
[2/2/2016 8:51:28 PM] - test EEPROM
[2/2/2016 8:51:28 PM] - test.hex builded
[2/2/2016 8:51:28 PM] - Uploading...
[2/2/2016 8:51:30 PM] - Uploaded
[2/2/2016 8:51:30 PM] - [arduino ide - serial monitor] Serial monitor connected to /dev/ttyACM0
[2/2/2016 8:51:36 PM] - [arduino ide - serial monitor] Serial monitor disconnected from /dev/ttyACM0
I'm not sure why your IDE is doing that, but the official Arduino IDE from Arduino.cc works on Ubuntu and does not have that issue. Download from Arduino Software download page.