Bicycle Mechanics - problems removing a Dura-Ace quill stem from bike

I'm overhauling a friend's Cannondale 3.0 that his brother gave him, and replacing the Dura-Ace 120mm quill stem (which is beautiful) with a Nitto Technomic so he can have his bars a lot higher. The D/A stem was made by Nitto and has a unique design; the bolts for both the quill expander and the handlebar clamp are hidden and recessed, accessible after removing a cap that screws in at 45-degree angle on the top/back of the quill stem. For pictures of this model stem, see the first few shots on Peter White's stems page (http://www.peterwhitecycles.com/stems.asp) or just look at this shot:
http://www.peterwhitecycles.com/images/products/Accessories/dastem3.jpg
Getting the bar out was easy, but I've not been able to get the stem out of the bike's steerer tube, or even get it to loosen. The expander is the "classic" sort that's not a triangular wedge, that sometimes can get stuck and needs to be tapped out with a punch or something. Here's a picture from Sheldon's site showing the diff between a wedge and an expander. The D/A stem has the expander design.
http://www.sheldonbrown.com/images/stems333-220.gif
But my problem doesn't seem to be that the expander is just stuck in the bottom of the quill and needs to be tapped out. Here's what's going on in my situation:
I loosened the bolt into the quill-expander, but the stem doesn't loosen in the steerer tube
if the expander were stuck in the bottom of the quill, I would expect that unscrewing/loosening the bolt would raise the bolt up
however, when I loosen the bolt that goes into the quill-expander, by turning it counter-clockwise, the recessed bolt actually becomes further recessed.
starting from as-far-as-it-can-go in the clockwise (typically: tightened) direction, I'm able to turn the bolt six and a half turns counterclockwise, and then can't turn it any further. It feels as if it got tight in the opposite direction.
I'm trying to make sense of this data, wondering what's going on. Is the expander reverse threaded? (Unlikely, as there's be no reason for reversing, and when I got the bike it was tightened all the way in the normal-threaded direction of tightened all the way.)
Does anyone have a sense of what's going on with this bolt? I'm assuming the quill stem is just frozen inside the frame's steerer tube, but I want to figure out any uniqueness about the stem's design before I start treating it as if I know fully what's going on.

Thanks for any help.

it would be a wedge it really doesn't expand it contracts as it gets tight try pulling the bolt out of the top of the quill

Except that the bolt is getting more recessed as I loosen the bolt (or at least as I turn the bolt counter-clockwise). It's weird.

Anyone have any experience with this stem and able to offer any advice or explanation here?

I am sorry, I am only familiar with the wedge style. Never knew that there was an expander type quill new to me. Although I believe that the expander quill was quite standerd in it's day. Maybe some WD-40 might help?

Most steerer tubes have a hole in the bottom. Remove your front wheel. Put the biggest drive punch you can into the bottom of the steerer tube and seat it against the bottom of the expander and then wail away with the hammer of your choice. That should drive out the expander. This also works fine with "escaped" wedges.

The common moral to this story is that all expanders and quill wedges should be greased liberally when you put them in. These guys are usually steel and just love to rust and get frozen into the steerer tube. Once that happens the stem comes out and the wedge, or expander, stays in. Soak with PB Blaster, let it set overnight and then attack from the bottom with hammer and punch.

I am fighting the same problem and same stem. the reason the bolt stops unscrewing is because the end of the bolt has been smashed so that it does not come out of the expander. I am not sure if the factory did this or past owners banging on the end of the bolt through the bottom as described above have peened the end of the bolt. I have attacked through the bottom and have been able to loosen the expander and I can see it loose in there. Even so the stem is still solid as a rock and not moving at all. Let us know if you get it out.

Oh and if you don't want the stem anymore I could sure use the cap screw!

Turns out there's actually a limit screw that keeps the expander from being screwed out all the way.

In my case, I'm pretty sure that the aluminum stem is frozen inside the steel steerer, and tried ammonia to attack the aluminum oxide but it didn't help in this case. So I'm just leaving the stem in there and my friend will have to deal with having low racing-posture handlebars.