To your first question... yes actually. That's a very common deficiet associated with attential disorders (ADD and such). In a neurological panel it would be illuminating, because that would stand as a single PORTION of an overall ensemble, not a single score. It may be that you find it easier to manipulate abstract concepts than you do keeping track of specific quantities. They are very different after all.I've seriously considered the learning disability thing in the past. Is there a learning disability that causes someone to not be very good with arithmetic, but still be good at all other forms of math? On the other hand, it may just be that I'm an otherwise average American who's good at physics. Whatever the case, I figure that if I've made it through four years of college, two years of grad school, and one PhD qualifier without any serious trouble, it's probably nothing to worry about. But I figure that I would probably score fairly low on an IQ test. The existence of people like myself doesn't mean the data presented earlier isn't perfectly valid. But it does mean that we should make ourselves aware of what this funny quantity we call IQ really means.
As you say however, you have nothing to worry about! You just happen to have some extreme strengths offset by a (harmless) weakness. My handwriting is terrible, but I make lovely calligraphy. I CANNOT improve my handwriting without approaching the spatial issue of writing differently. Does it matter? Not really. I learn foreign languages through immersion freakishly quickly, but a textbook might as well be in Attic Greek if it uses paired-word association.
What is IQ? A historical blip on the rador, like Phrenology, or Phlogiston, or the Aether. lol.