ZD won't download Yahoo mail before Nov 2008

[foratrade]

I'm new and after downloading the first 2,000 or so emails from Yahoo, ZD stopped and gave me this error:

Failure communicating with remote server. Please try again later.

Debug message: Connection is closed

Exception:......
...........

I've tried for several hours and keep getting the same error message. If I restart, it will retrieve the new mail but won't go back and get the other 20k emails dating back another 6 years.

Please help.

Thanks