[cisco-voip] Phone hitting wrong voicemail account?

[TechGuy]

I am confused... got a issue with a user reporting that they keep
getting "invalid entry" after putting in their password when checking
voicemail from phone.

I thought well sounds like she forgot the password, so I reset it.
But it still happens.

Odd.. but I assume its user error as the phone config looks fine.

I go check and do it myself, sure enough same thing.

I reboot phone.  Same thing.

I delete phone and add it back.  Same thing.

I delete the second line on her phone, shared line of her supervisor,
and the issue goes away.

Add the second line back issue reappears.

I can't say I have seen this before.  I have many many phones out
there with second and third shared lines but this does not interfere
with the user checking voicemail.

It seems that when I add the second line and hit the messages button
that its hitting unity with the second line and thus is expecting the
password of that line / user.

Any thoughts and suggestions, other then just keeping the second line off.  :-)