Just bought a brand new Uno R3 Plus as I thought my old uno R3 Plus had a problem... alas same issue.
I tried reinstalling Arduino with no luck
I am using Mac OSX 10.9
I selected the correct board under "Tools".
Connected the USB cable to it and see the green "ON" led light.
I selected the serial port "/dev/tty.usbserial-AD01V737"
I opened the example "Blink" and clicked "upload"
I am getting the following:
Using Port : /dev/tty.usbserial-AD01V737
Using Programmer : stk500v1
Overriding Baud Rate : 19200
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: Send: 0 [30] [20]
avrdude: ser_recv(): programmer is not responding
avrdude: stk500_recv(): programmer is not responding
I see the Rx LED blinking when I try to upload the program