Cannot add yahoo contacts in windows live messenger

Hi,
I am using windows live messenger 8.0. The problem is that. I cannot add yahoo contacts in windows live messenger. I cannot see any contacts in my list. Can anyone solve this?

Thank you in advance.

When you add a Yahoo contact, you have to add them as username@yahoo.com in windows live messenger. You can also create your own Yahoo ID for free at http://messenger.yahoo.com It is more reliable then the Yahoo functionality within Live Messenger. You can enjoy all feature of messenger with the real client.

Your must of add Parental Control, to change this try to change your birthday or year in your profile at hotmail.com. If you are under age on your profile, it may restrict you to add contacts in your list.

The following may cause this problem:

• You may have deleted this contact by using another program that uses the same address book.
• Your contacts may not have signed in to their Messenger accounts in more than 60 days.
• A cache file in Windows Live Messenger may be corrupted

Re-add contacts from your allow list to Contact list. If your contact list is empty or incomplete after you upgrade to Windows Live Messenger, the cached contact list may not have updated correctly. Delete two folders in the contacts folder in C:\Documents and Settings\Local Settings\Application Data\Microsoft\Messenger. Sign in to messenger again and try.