Check out this list of problems LinkedIn has… posted on Recruiting Blogs: LinkedIn: a List of Challenges.
The first (and right now the only) comment, by Jennifer, suggests that some of the challenges are really user issues. I agree with that, although it’s no secret that plenty of people have issues with LinkedIn stuff (except LinkedIn, of course).
Go through each of the things… are you aware that each point is a challenge? If yes, how do you get around the issue? If no, perhaps you aren’t using LinkedIn deep enough to realize there should be another way?