I would think that *something* significant had to change between rev. C and rev. D. I had a multilink with and older rev on my XP machine (I don't remember what reve) and CW wanted to update it. I just said "yes." You might want to make sure you're running the same version of CW on each of your machines. An older version of CW may not correctly recognize the new rev. of multilink.
-Tomahawk