Thanks. Exactly what I needed. I purchased 0.4, 0.6 and 1.2mm to try. A 10 speed chain would help, but on my 10spd set up, my chains only last about 1k miles, where my 9spd chains on 9spd drive trains go about 3k miles.
Also, the length of your chain stays will make a difference. (The longer, the less chance of a problem.)