I tried making white chocolate ganache for this first time this weekend. I mixed three parts white chocolate with one part heavy cream (using the method here  http://www.inspiredbymichelle.com.au/).  I followed the instructions, I the second day I let it come back to room temperature but when I started mixing with my rubber spatula, it started separating and became very oily.  Any ideas? I want to try with dark chocolate, but am afraid of ruining another batch.

I would still use this method for dark chocolate. The problem when using white chocolate is that there is no actual cocoa solids in it meaning it is mostly made up of fat and sugars this is why there is a lot of oil in the mixture :)

Thanks for the responses.  I did pose the question on the you tube site as well, with no answer yet.  I am going to try with the dark chocolate today and see how it turns out.  Thanks again!