No idea what you were clicking on but it works fine for me:

YouJediJunkie wrote:If it doesn't work with the mod tool... [Diet Dr. Pepper], then I am doomed.

I think you're confused, you don't need the plugin to use Roadkill, the plugin just allows you to use Roadkill interactively within XSI, without the plugin you will have to export your object to Roadkill manually and then import back into XSI manually, where as the plugin does this for you if it is installed to make it an automated process.

Oh, I've just been stupid. I've got my model in Roadkill now, and everything seems to be fine! THANKS a bunch!