Is it true that the 10 uF capacitor isn't needed to program an attiny84 from an arduino duemilanove?
A 120 ohm resistor is recommended for boards with an FTDI converter. Various folks have reported success using either a 120 ohm resistor or an approximately 10 uF capacitor. The third choice is to cut the auto-reset enable trace.
You will have to do something to disable the auto-reset.
I'm asking this because I've seen different schematics for duemilanove and uno.