We had a similar problem with Jakob. His Dr administered a reading test when he was 8. He read the paragraph out loud correctly, and the dr showed it to us. Every word with more than 4 letters had the interior letters reversed. (Boat was Baot, for example) she then showed him a second paragraph which he read correctly. It was the same paragraph spelled correctly. with the two paragraphs side by side he was unable to identify any differences in the paragraphs. Well, he did notice that
one word was misspelled.
Basically, he was reading with only the right side of the brain. the right side recognizes the first and last letters and the lenght of the word. The left side recognizes the interior letters. Both sides of the brain don't integrate until 9 years - so she wasn't terribly concerned, but did prescribe several courses of physical therapy focusing on balance, and cross body integration, she also wanted him to swim a lot - that cross body thing. (This is the reason our school delays having children read. Though spelling is started off right away. Of course, by the tiime they start "reading" they've pretty much figured it out on their own.

It makes for a pack of 3rd and 4th graders who are voracious readers.)
The good news was that even handicaped like this he was still reading above grade level. She said he had an astonishingly large "dictionary" in his head.
He still has trouble with interior letters. Calm gets pronounced Clam. But, it's getting better as his development catches up with his peers. At least he's seeing the problem when you draw his attention to it. I think he got into the habit of being a lazy reader and only looking at the first and last letters and the length of the word.
Don't know if this helps...