[Y!M] trouble adding contacts

[Patrick]

We have been having trouble adding contacts onto my wifes messenger
account. We have had friends and family that we have been able to ad
to my account but not my wifes. We are using the same computer with
the same version of messenger on it. When we try to add someone as a
contact on her account they never receive the invite. If we try to add
them on my account they see it immediately. I tried asking about this
on answers and got no takers. Hope someone can tell me what I may check.