Switched my yahoo webmail to the new Mail beta yesterday. I'm using Thunderbird 3.1.6, Webmail 1.3.10 & Webmail-Yahoo 1.4.7. When I started up Thunderbird on my laptop in the evening I got the could not sign on negative vibes message. This morning at work same thing. I went and switched back the yahoo webmail to the current stable version and all mail started flowing into Thunderbird with no problem.
Looks like Webmail-yahoo may need an update to be compatible with the new Yahoo Mail beta JK
