I kept getting the "negative vibes from yracc_@yahoo.com" error and I checked up on Yahoo Mail...
The Beta is now no longer Beta, and they are switching their accounts over to the new server already, so I found (for me at least) that updating the webmail Yahoo plugin to the Yahoo Beta website fixed the problem and I can now download my messages again. By the way, I also had to update my yahoo mail account to the new yahoo mail because I had never switched to Yahoo mail beta...
Thanx
Brian