MSN Messenger & Yahoo messenger

Hello,

I have both a hotmail & yahoo email account & have contacts signed up for my my msn messenger & yahoo messenger accounts. When I sign into my yahoo mail, and set the new side bar chat to show my status as "invisible", I appear invisible to my Yahoo messenger, however, I still appear "online & available" to those on my MSN messenger contact list. How can I preven this? If I sign in as "invisible" when checking my yahoo account, I do not want to appear online to either the MSN or Yahoo messenger list!!!!

Thank you.