Hmm, well basically I started by copying the layer from your project and pasting it into the corresponding layer in my Logic 8 project. I also did this in the clicks and ports layer as well, so basically the environments are identical.
Now, in the arrange when I try to select 'Rounik's Step' for the channel, it only gives me the options to select individual rows, not the entire 'Rounik's Step' like it is selected in the channels in your Logic 9 project. And even if I do then select the individual rows, nothing seems to play. Transport is obviously running, I've got sound on the instrument when I play it from the keyboard etc.
I guess I am missing something in the Mixer layer, but I haven't been able to figure out what I am not cabling correctly... If you have any tips let me know, otherwise I'll just keep drilling away at it until I figure it out.
At least I know it will work in Logic 8, so that means the error lies within something I am not doing correctly and not a compatibility issue.