Yahoo messenger help

My sister is running Windows Xp Home. Since about 3 weeks ago, she can not recieve offline messages on some of her profiles. If she is online and chatting she can get them but if she is not online then she does not recieve them. One of her profiles that she hardly uses and only a few people knew about she can get offline messages. She thought somebody stole her password so she requested a new password. Even with the new password still can't get offline messages. Uninstalled yahoo messenger and reinstalled it and still can't get offline messages. Any ideas?