I feel your pain. I have a 7 year old son with ADHD and he does the same thing. It makes for such a horrible day when you have to be on him all the time to get things done. If it's not one thing it's the next. He totally has the ability and is a gifted child to boot, but he has no motivation at all.
SO, I put him in public school the end of January. He'd never been there before and he was SO excited to go. NOW, he's SO excited to homeschool again, lol! It wasn't all it was cracked up to be and the homework is a pain! He gets home at 3:30 and sits down to do it. He's usually not done by the time I have to get up and make supper. Then he has to work on his own. After supper it's back to homework. Sometimes until bedtime at 7:30! Then it's back up at 6:30 the next day for the bus at 7:30. He's also not any more cooperative with the homework than he was with the homeschool work. But the big difference is that now I have no idea what he's been taught and how to do their lame math worksheets. Plus my son is gifted and is now reading 2nd grade books instead of the 5th grade books he normally reads. SO, I figure by the end of the school year he'll have learned nothing above and beyond what he learned here during the first 4 months of the school year. I might as well have just ended our school year in January and threw in the towel.
My advice is to revamp your program. If it's a battle you need to win, just tell him that you have done all you need to in that cursive book this year and now it's time to do other things. Get lots of books from the library and let him read a lot and work in subjects that he likes better. I know from experience, that when it's a battle of the minds, you can't give in, but you can revamp, because that still leaves you in control of what's going on :o)
Best wishes with the new baby, and the rest of them :o)
Jennifer
Mom to 4, ages 8, 7.5, 7, and 5, ttc #5
foster Mom to 4 more, ages 12, 8, 6, and almost 2 :o)
It's a crazy life, but it's my life, and I happen to like it :o)