Common admin 'problems'
Aspergers, as noted.
Attention deficit disorder - when problems arise, one needs to be able to shift gears quickly. People with ADD generally do better at this than those without. Also, it appears to me that many people with ADD notice those little things a lot more - that's part of why they're so easily distracted.
OCD - depending upon ones exact compulsions, this can either help or hurt. But if an admin has both a clean desk and an organized filesystem, chances are good she has OCD (well, possibly 'he', but the odds are against it.)
The 'beta tester' syndrome, as noted above but not named. If you're an engineer and you want to ship a nigh flawless problem, you love having a few of these on your beta test team. Pretty much everyone else wants as little to do with them as feasible. (Unfortunately, that means that many managers actually *remove* them from beta test teams, to try and make their ship dates - and so the astounding problems happen more out in the field.)
The 'admin field' effect. This is a problem in the traditional sense, despite it not appearing at first glance to be one, because when ones mere presence makes things work, it becomes incredibly difficult to diagnose why they don't. Note: in my experience, the effect is very temporal: the field goes away almost as soon as the admin goes away; the biggest reason that the user stops complaining is that they feel increasingly stupid for having the problem, the more times the admin comes and the problem goes away. At one of my earlier jobs, I was assigned to share a cube with the strongest "beta tester" at the company, in an effort to counteract her syndrome. (Did not work at all - my field is apparently specific to unix OSes; she ran Windows.)
dyslexia - not sure how this helps, but it sure seems we collectively have a lot of it. (Note: has various forms: verbal, auditory, visual...)
I'm certain I've missed at least one, possibly more.