I just got back from the apple store. The guy in the store showed me some neat stuff my macbook and iMac can do. He showed me screen sharing and remote access features with my .mac account. When i got home i was able to access my imac from my macbook and vice versa. I only seem to be able to do this when i'm in the same area. When i'm at work with my macbook i'm unable to access my imac at home. The sales associate told me i should be able to do this. Any info or advice on what i'm doing wrong?