I just upgraded to the lastest Arduino 1.0.3.
I'm on Mac 10.7.5
I dont believe I need to add any new drivers.
Ran an Uno just fine a year ago on this computer. Just bought this on Jan 2nd:http://www.amazon.com/Arduino-Rev-3-Uno-R3/dp/B006H06TVG/ref=sr_1_1?ie=UTF8&qid=1357450019&sr=8-1&keywords=arduino+r3
When I plugged it into my USB I get the red ON light and a steady red pin 13 light.
When I upload a sketch I get some green flashes from the rx/tx lights, pin 13 led dances a bit, then it goes solid. In the console i'm given this:
avrdude: stk500_recv(): programmer is not responding
The fact I can get the rx/tx lights to dance when I upload a sketch makes me think one thing - but no matter how I troubleshoot it I cannot make any progress. Help widely appreciated!