I have been working on a multiple RGB LED project, with an 08M2 I2C master, sending signals over 4 conductor cable to TLC59108 LED drivers on separate boards, daisy-chained together. The problem I'm having is on the LED board furthest from the master. It usually works but occasionally will stop working, and i'll have to disconnect and reconnect power to restore it. I'll post schematics later, but the I2C master board is just the 08M2, the download circuit and jack, power jack for a wall wart, 22uF capacitor for filtering, a 4 pin connector to hook to the LED boards with +, -, SDA, and SCL. The two 4K7 pull up resistors are also on the I2C master board. IIRC I also have a decoupling cap for the 08M2. On the LED boards is two 4 pin connectors, the RGB LEDs, TLC59108 and the necessary components to make the TLC59108 work. I'm thinking there's an issue with capacitance on the SCL and SDA wires, or possibly crosstalk. I currently have SCL and SDA on one twisted par, and the two power on the other twisted pair. (wires pulled out of cat5 cable)