My impatiens have black spots on the leaves, and so far, I haven't been able to identify what precisely is causing this. Does anyone have any clues? It's really aggravating, especially since I am about to propogate the same plants. Should I even try it with these?
I would appreciate any suggestions.

Have you had a lot of rain?? Could it be a fungus or mold??? We have had sooo much rain here in maryland and a lot of my flowers got black spots on the leaves....my red salvias did that then they all just died......I think the rain was the culprit....plus the mulch...not letting the air circulate....I had to pull them all out and replant in that part of the yard.....

Thanks for the rain idea! As a matter of fact, it did rain a lot here...every day for 2 weeks, and several times a day. I've been picking the affected leaves off, and so far, it doesn't seem to be dying...it just doesn't look too swift at the moment. Impatiens are sort of a challenge here for me in Florida...they're too sensitive for full summer sun, and yet, you have to be careful not to get them too wet.