Help: Can 2 Diff Pro2s partner w/ same computer?

[gemilove]

My wife and I both have pro2.
my wife has 4g SD and I have 16g SD.
Prob is when I try to sync my music w/ windows media player.
I had my pro2 connect to the wmp and named the sd "john-16g" and synced all my music. then when i try to sync my wife's, it keeps on saying "john-16g" even though it correctly sees only 4g.

is it bec wmp is confused w/ the same phone?
bec it says john-16g, if i take out some playlists wouldn't it mess up my phone's SD?

I know, this may sound a little confusing.
but i need help!