"Focus soft limit reached" msg when Rack Focus???

[obrienimages]

I'm using ML in a Canon 5D MKII with a Canon 2.8 24-70mm zoom lens.  When I try to set up Rack Focus I get the this message about sift focus limit reached.  I see other users with the same body and lens have listed this problem. Anyone know what's going on? (My lens is in excellent condition ... it's not a mechanical problem with the lens)
Any suggestions appreciated...