Here’s some more info from my setup.
System:
OS X 10.5.6
IDE Version 0016
USB driver FTDIUSBSerialDriver_v2_2_10.dmg
ATMEGA328P-PU
IDE settings are correct
Tools > Board > Arduino Duemilanove w/Atmega 328
Tools > Serial > /dev/tty.usbserial-A70076ay (tried cu.usbserial as well)
Arduino board - purchased from ebay.
Upload works fine using XP via bootcamp.
Here’s the console output:
avrdude: Version 5.4-arduino, compiled on Oct 9 2007 at 11:20:31
url line removed
System wide configuration file is “hardware/tools/avr/etc/avrdude.conf”
User configuration file is “/Users/MYUSERNAME/.avrduderc”
User configuration file does not exist or is not a regular file, skipping
Using Port : /dev/tty.usbserial-A70076ay
Using Programmer : stk500v1
Overriding Baud Rate : 57600
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
avrdude: Send: Q [51] [20]
avrdude: ser_recv(): programmer is not responding
avrdude: stk500_recv(): programmer is not responding
RS light blinks 3 times. I reckon thats the avrdude: Send: 0 [30] [20] bit.