I don't have the link right now but there was a Flickr forum post in which a lot people chimed in on this. A lot of people tried the 44-2 all through 44-6. The conclusion was that the only one that doesn't hit the mirror, was the 44-6. Maybe there was another model also, but I'm not sure. I have the 44-6 and it doesn't hit the mirror on my 5Dc.
(44-2 through 44-6 are different batch runs of the same lens, through different decades)