I don't have the time to read the other thread linked - wow, 9 pages! - so I don't know if this is addressed there. But my son had a significantly lower processing speed, too, and a 'significant weakness' on the picture concepts subtest, despite having scores quite similar to your child's. our tester told us this was common, not to worry about it. it niggled at me for a year, before I finally, just to stop the niggling, took him to a behavioral optometrist and discovered his right eye flickers on and off, his eyes are mis-aligned top to bottom (one sees half an inch higher than the other), they turn out, he has double vision, and is slightly farsighted. It was shocking - she'd say, look at the dot on the wall, and he'd say, which one? Now we are looking at doing the vision therapy. It feels very weird, b/c, as he says, he's already the best reader in the class! How can his eyes be bad? But I hear tell that it can really help their processing speed not to have to make such an effort to do that reading, and that many kids make great leaps after therapy. Makes me feel bad, imagining the poor kid. He was a late walker/jumper/etc, and I read around in developmental delay books and thought he had some sort of a motor planning problem...well, no wonder, when he sees two of everything and not at the same level! No wonder, too, he makes what seem like sloppy errors adding columns...the numbers are doubled and jumping around!
so maybe maybe there's something like this pulling the speed down in your case, too?
