DS6 knew his letters and sounds around age 3, but stubbornly resisted learning to read, and at age 6, he's still struggling to read IMO. He has a lot of DH's reading problems. DH still can't sound out new words, like unusual names or words in another language, correctly. Both DH and DS will read letters backwards, insert sounds that aren't in the word, skip sounds that are there, etc. Meanwhile, DS6 is two years ahead in math, and we've been talking about physics, math, death, god, infinity, and mechanics since he was three.
Just a thought here, but have you had your DS evaluated for dyslexia, visual tracking and convergence issues, or problems with visual or phonological processing? Any of these alone or in combination could cause these sorts of issues, and there are interventions that can help all of them - but not unless you know what exactly you are dealing with.
