I am using an Uno for both the programmer and the target. This example notes that if you are using an Uno, you need to add a 10 uF capacitor between reset and ground. I cannot discern if the programmer or the target requires this capacitor. Anyone know?
I used many times an Arduino Uno as ISP programmer (I followed the instructions from here: http://pdp11.byethost12.com/AVR/ArduinoAsProgrammer.htm ) and I have never needed a capacitor. I will try to put one to see if there is some change, some improvement.