Question for the AD/HD mates re building your own safety net

I really appreciate the viewpoints posted by the AD/HD mates especially as my husband sometimes doesn't appear to be/want to be introspective enough to give me similar feedback.  

My question is with regard to feelings like feeling you "can't do anything right" especially in relation to messing up the same things over and over, and still seeming surprised at the result.  He definitely feels this way at times and we're both frustrated, but the obvious answer is to be aware you have trouble in a certain area and try to minimize it as much as possible.  Every book says this, every conference session says this, and we've discussed it personally that he needs to do this; yet he dosen't put the safety nets in place...even when it only needs a simple checklist.  I understand thinking/doing things differently, but I don't understand not taking the action to be sure that other people get what they need from you.

For example:  We are self-employed & a couple times a month he has to invoice.  He has frequently sent in inaccurate invoices because he didn't check carefully to be sure that he was including all the work that he did.  It has always been able to be resolved, but it's an unnecessary and frustrating step--for both of us AND for the person improperly invoiced.  I've offered to take over the invoicing as it is clearly not his strong suit, but it has become such an important thing in his mind to be able to do that he won't give it up.  Ok I understand this, but then why not take GOOD care to be sure you do it correctly. 

We've tried several things, and our most successful endeavor is to have me check it before he faxes it in.  That has worked very well as I catch any small errors before anyone else has to deal with it, but after a couple months of having no issues he now is faxing them off after having "forgotten" to let me check it.  So far they are still correct, but it is like he no longer thinks he has any issue, which just isn't true.   He uses the past month's invoice as a template and basically changes dates of payment due, dates of service, invoice numbers, etc--sometimes he messes up the invoice numbers (which are supposed to be based on the date the invoice is generated), sometimes forgets to include a service because of a reschedulation, sometimes he doesn't change the dates of the services, sometimes he forgets to change the date due.  Sometimes, and this is the worst, he forgets to fax it in on time and then we have to wait longer to be paid.

We both agree that simple checklists for these types of repetitive actions would catch any of those little attention errors before he sends it off.  We've been discussing checklists for several things for at least a year.  He WILL NOT make them.  What the heck is up with this?? 

He accepts he has ADD and that he needs to do some things a little differently & is on meds.  I think if he'd come up with the checklist idea that maybe he'd be making them, but since it was my idea, he doesn't do it--this resistance to other people's ideas when he has no plan of his own is one of my biggest causes of frustration.  For this reason, I don't see any value to me making them for him because it is like a stubborn child saying "I wanna do it myself" not in words but definitely in behavior.  If I make the checklist, I seriously doubt he'd use it consistently because he hasn't *bought into* the idea enough to make it his own.