Yes, my friend's ds - well, he's 8, but near enough. He reads brilliantly (eg., Harry Potter) but his spelling is atrocious as is his handwriting.
I also agree with Jan - some people just 'can' spell and some can't. My Mum is very bright, was a teacher, but she can't spell for toffee. And she loves crosswords - not a good combination. I can spell (cue for someone to go through all my posts and find spelling mistakes) and if I'm there she asks me how to spell every second word I can generally 'see' if a word is spelled incorrectly - my Mum can't.