I can't open some email attachments in the upgraded version but can when I switch back to Classic email?

A Yahoo posting suggests that you disable scanning attachments in your anti virus software.If that fails go back to classic mail Hope this helps.

There are a few reasons why your attachment might not appear correctly: * You might have problems viewing an attachment if your browser is not properly configured to view that type of file. Usually, the easiest solution is to upgrade your browser to the most recent version: Download the Firefox browser at: http://www.mozilla.com/firefox/ Download the Internet Explorer browser at: http://www.microsoft.com/windows/ie/downloads/critical/ie6sp1/default.mspx * If you're having trouble reading an Adobe PDF file, you'll need to install the Adobe Acrobat Reader, which allows you to open and read these types of files. For more information, visit: http://www.adobe.com/products/acrobat * You might also have problems viewing an attachment if it was sent in an unreadable "encoding type." When a message is sent, the sender might be able to choose an encoding type. If possible, the sender should use MIME encoding.