I was able to resolve my issue but it took a while on hold with Sony; I'm guessing because I called near the new year break. I'm not sure if Snow Leopard is a factor because I only have Leopard but in my case the issue was not Mac related and I read from another thread that ADE for Mac doesn't work (i think from jim?) anyway check the MobileRead Troubleshooting section for the thread.

I really hopes it works out for you.