Here's an update on this:

I took cuttings and placed them in a glass of water on a window in my garage. A couple of days later, I found tiny little ants crawling all over the cuttings. This may be what caused the plant to get sick in the first place. I assumed the cuttings would be lost, but in a last ditch effort, I sprayed some and killer on them. I will get a more specialized mite killer or something, and try again. If I'm lucky, these wont die, if not, try and try again.

I propagate them with 100% success by simply putting the cuttings in water in the kitchen window [eastern face, 2hrs. of sun]. They root in about a week. Be sure to change the water at least once a day.

To get rid of the ants, put ant baits in the pot under the plant for days when there is no rain forecast. Or put ant killing powder in the pots [less effective]. Ants will be gone completely in about a month.

If the cutting is infested with ants, submerse it in water overnight in something the ants can't crawl out of -- like a tall glass jar since they can't climb out of that. The next day, the ants will have drowned, the Impatiens will be fine.

Note that sometimes Impatiens get shocked by being cut. Just because the cutting initially looks like it's wilting and dying, doesn't mean it's a gonner. Leave it in water and you'll find that most of the time it will eventually acclimate and perk back up [I have some that are currently doing just that].

Hope that helps.