Hey semidevil,
I'd say that your feelings are perfectly normal too.. I can't relate to the boyfriend/girlfriend situation because my fiance' detests the computer, but my dad has a horrible habit of doing that to me when I call (and I have to spend money on long distance to talk to him)..
My dad plays card games while he's on the phone rather than chats, but he's just as distant & I get really tired of having one sided conversations with him.. After all, if I wanted to talk to myself, I could do that for free..
It is disrespectful and very frustrating, but can you prevent it? I don't know.. You could either ask her if she's busy when you call and/or tell her that you have to go (without any explanation of where or why because she probably won't be listening anyway) if you hear to many generic responses.. I also liked H.Kondriac's suggestion about asking her to call you back when she could give you her full attention..
In any event, if you do decide to confront her about her lack of phone etiquette, just make sure you do it face to face.. Otherwise, it's likely to go in one ear and out the other.. Good luck!
Take Care,
Melanie