Herwig -
Yes, your interpretation of the layers is correct. Whether the power layer the second layer or the ground layer is second, we will need to try and dig up the design files. It shouldn't necessarily make a whole lot of difference; while I agree, ground typically is the second layer, that isn't always the case.
We'll work on digging up the gerber files for you. Can we use your email address in the profile to provide this information/files to you?