HoneyBadger - the last link you provided is pretty much exactly how a developmental paed I recently heard speak described inattentive ADHD (he was speaking particular in gifted kids so maybe it's different in other kids, I don't know he didn't say).

Listening to him speak I realised that both my eldest and my husband have inattentive ADHD and that my middle girl possibly does too, though milder and without the co-morbidities.

Can I suggest you ask yourself why you think your DS has all the issues on the list but not ADHD? If you throw out preconceived notions of what inattentive ADHD is (mostly mine came from poor media coverage and hear-say) and think of it as this list then is that a good fit for your son? It's a great fit for my son. In fact that article was a great discussion of my whole family.

I am not sure if reading that article was a trigger for me or not but after a really hellish fortnight I completely collapsed in a heap this morning. Holding my family together - getting out of the house in the morning, getting homework done, dealing with the constant noise, dealing with my eldest DD going straight to a rude, angry, mean, or accusing tone of voice... Being the only person that has any sense of time, has any sense of needing a plan, of needing to adjust the plan.... it's just utterly exhausting.

Things that have helped us are

1) strict elimination diet, we use this one:

http://www.sswahs.nsw.gov.au/rpa/allergy/resources/foodintol/handbook.cfm

2) an iPod touch for my 9yr old which has an app called Home Routines set up with everything she needs to do:

http://www.homeroutines.com/

The iPod touch has changed our lives. She's had it about a month and within a week was getting ready for school on time with all her chores done every day. She was self managing her home work and not playing until everything she had to do first was done. And we've packed it with educational games. And she loves having her own music to wake up to in the morning. And we can confiscate it for truly terrible behaviour (this has only happened once or twice and she still gets to use it for "work" but not for "play").

But it's still not enough, we need more help and I am at my wits end. She's being assessed in September. I need to get DH to agree to be assessed too. And probably my middle girl as well...