Format Plugin: Writing a layered image

Hi,

I have been trying to implement a format a plugin for a format that supports multiple layers. The issue is that the layered format example from the PS CC SDK does not work with PS CS 5.1. When I try to save a file with layers I get a program error message. I also tried the CS5 SDK and the resource file does not know what "FormatLayerSupport" is, so it won't compile. How can I support layers while also supporting versions of PS before CC? Thanks.