Mike(Ecosamurai), could you describe, with as much detail as you can give, how you are approaching/training the rowing exercise and what, specifically, you're developing by training this?
When I do it I'm trying to feel my one point as it moves. I'm also trying to feel the ground. I dunno how to describe the feeling properly but you just kinda have to feel the ground making you powerful it isn't your arms or any kind of strength. So I suspect its pretty much what Mike talks about often and more eloquently than I do so refer to his posts.
I would also recommend trying it as often as possible with a partner or friend holding onto your wrists, their presence and weight gives you lots of feedback as to where you are moving from. I have a student who is >6' tall and about 250-260lbs and I can move him without difficulty when he holds my wrists even when he tries as hard as he possibly can to stop me. If you push through with your arms in any way it becomes impossible. The movement is: in this order: bend the knee> extend the wirsts> bend the knee> withdraw the wirsts. If you move your wrists before your knee your partner will stop you easily. If you do not keep your back straight and head up, your partner will be able to pull you off balance or push you off balance when you withdraw your wrists. If you do not have ki extension and weight underside you will find your partner smashes into your chest as your arms get pushed behind you (sometimes they collide with you anyway but this shouldn't be a problem if you are properly coordinated).
Hope that helps.
PS - I am now officially unplugging from aikiweb for a while, I hung around as long as I could this week but I've really got to work on some other stuff now.