I have been an Yahoo Mail User for over the past 10 Years. After the recent turbulence in Yahoo Management shaking the rank and file of engineers, the new ones suck pretty badly rolling out untested products without means of error reporting.
Yahoo! in all its capability has tried to Copy Google and used AJAX based interface, but little do they realize how badly it performs even on a 1 Mbps connection and Firefox browser. I normally don’t complain unless it becomes a real pain for performance. I am attaching a screenshot of one of the error messages that I am getting.
Yahoo! fix the errors and roll out tested products no matter what technology you use make it a lively consumer experience and not a sucking one as it is today.