Remote desktop issues

[axeldtf]

I own a macbook and an imac both running leopard. I use the remote desktop feature when i'm in my house between rooms. This feature comes in handy. Lately my girlfriend has been using my laptop and when she is on it at her house i can see her and my macbook on my finder window. However when i'm at her house i cannot find my imac on the macbook finder window. She has a belkin router and UPNP is enabled. Is there any other settings in need to adjust on her end? Or do i need to adjust my router on my imac's end. I like this feature and it's pretty much the only reason i have a mobileme account.