I'm still not 100% sure why it's happening, however it seems that when the component was removed from the application it wasn't totally removed from the registry. I manually went through the registry searching for that component name and dll file and removed all references to it. After that I was able to add the DLL again like I should have been able to from the beginning.

Hope this helps anyone else who may run into something similar int he future.

Cheers
-Luke.