This combination won't always (not often) pay attention to the focusing commands from the application. It also gets a lot of time out errors. I am assuming the problem is with the lense since the application works smoothly with another Canon Lense (though not macro).
Anything I can do to get the lense to pay attention! (i.e. work)
I will add that using Canon's EOS utility I have no problem using the > >> >>> focusing method. The lens gets each and every command. This is opposed to Helicon Remote, which seems to have problems getting the lens to pick up the commands.