How can I check if the CC and BCC is valid or not?

Why is it when I click to, cc or bcc i am unable to to check a persons name to include in the email?

• When I do the above, most of the addresses are shadows and cannot be checked

• Answer:

  Yahoo is still having some problems at the moment. Cures range from Update Adobe Flash Player and Javascript to clear IE7 cache, cookies, and browsing history. Different things seem to work for different people. It's causing attachments to not show, 999 errors where it won't let you do a particular action and some people cannot send recieve delete or move mail. It's not just Vista either it's happening to some of us on XP. I have been advised to use this site to view my mail, www.mail2web.com if all else fails go back to classic mail via this link. http://us.mg1.mail.yahoo.com/dc/optout?script=no click yes when asked do you want to opt out. Hope this helps.