Does anyone know what could cause SolidWorks to give me this error?

"Cannot add. This material is already on the favorites list."

I accidentally removed a custom material from my favorites list, and when I went to re-add it onto the list it gave me that.  I've restarted SW, my computer, searched the help, etc., but I cannot figure out why it is telling me that when it is most certainly not on the list.

Any help would be greatly appreciated as it is the material I use 95% of the time and I'd hate to go through the dialog every time.

Thanks