I should add:
- searches work fine, I get plenty of results from one to four stars (as configured)
- uploads work fine, I see the incoming searches normally, and someone is grabbing a shared file off my computer now
- I have the same problem no matter how many stars something has (though I typically just try 4 star items)

The only problem being, as described earlier, downloads never start. The ALL "wait for busy". I didn't have this problem until I upgraded earlier today.