If you have simply copied the files in the Vegas plugin folder it won't work. Both files use the core engine of WinMorph.
Install WinMorph and the setup will give you the option to install the plugin for Vegas.
I'm of the impression Winmorph is incompatible with Vegas 4. The last I read at Satash's site is that the stand-alone is the only way to go presently under Vegas 4.
I hope I'm wrong and someone can steer me in the right direction as this plugin has huge potential.
I suggested standalone operation only if there were persisting problems, which happen only to a small percentage (which i was not able to find out why, so i will be rewriting the interface to work better with Vegas). So first give the plugin a try with Vegas, and if we are unable to get it working then use standalone.