[Solved] ATtiny85 only uploading once (using an uno)

I'm uploading my sketch to a ATtiny85 using a Arduino Uno (like so), however I'm experiencing issues with avrdude when it comes to uploading.

I am using Arduino 1.0.5 setting my board to "ATtiny85 (internal 1 MHz clock)" with the programmer set as Arduino as ISP (and yes the Uno is running the sketch ArduinoISP). I'm using the ATtiny drivers from this website.

Initially I managed to program the blink sketch just fine after trying each USB port. Even then I had to reboot before I could get it to work. But I also noticed that sometimes if I reboot my machine (Macbook Air with USB3) just before uploading a new sketch, it will work on the first upload. But as soon as I try again, it will fail with:

avrdude: please define PAGEL and BS2 signals in the configuration file for part ATtiny85
avrdude: Yikes!  Invalid device signature.
         Double check connections and try again, or use -F to override
         this check.

Other times it will tell me what device signature it was expecting, and most of the time I get:

avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)

Any ideas where I'm going wrong?

jamesingham:
Other times it will tell me what device signature it was expecting, and most of the time I get:

avrdude: Error: Could not find USBtiny device (0x1781/0xc9f)

Let's start with that one. You have the wrong programmer selected.

As far as I can tell I have it setup as it is supposed to be.

I haven't made any changes to the process I'm doing and I get varied results.

(deleted)

Hey, I just tried that (I was unaware of this option, so thanks), but i'm still getting this error:

Binary sketch size: 836 bytes (of a 8,192 byte maximum)
avrdude: please define PAGEL and BS2 signals in the configuration file for part ATtiny85
avrdude: Yikes!  Invalid device signature.
         Double check connections and try again, or use -F to override
         this check.

(deleted)

I was just checking my wiring when I noticed that the LED I'm using to test the blink script is affecting the upload. If I remove the LED and any other components I can flash the ATtiny85 fine, but if I add the LED to pin0 & GND I get the Invalid device signature error.

The weird thing about this is I have (at least twice) managed to upload my sketch with the LED in place yesterday.

Anyway, solved. Thanks for the help.

(deleted)

Yes, but a 220 Ohm resistor. I was just watching How to Build an AVR Development Board - YouTube and here he states that you can get interference, so that was probably what was giving me problems.