I've got two littles, and have really only been welcomed by one. My first little had basically dropped off the face of the earth, and no one from the chapter has heard from her since she left school. I see her maybe once a year at Initiation, if she shows up. What sucks is that we're both living in the same city (I'm an alum) so i'd love to be spending more time with her. But, it's a two way street, so if she doesn't want the contact...my second little and I are a lot closer and talk at least once a month, if not more. Lots of emailing, though!
It's hard when you're alum, because your life doesn't always automatically include thoughts of your GLO. It's easier for me to think "Gotta call my little" because I sit on our chapter advisory board and oversee two executive positions, which requires me to be in contact with each exec member once a week. It's tough, because I still feel like I'm not in contact as often as I'd like...but again, the big-little relationship takes two. So, I think all of us need to stop feeling so bad, 'cuz our littles know how to get a hold of us!

(Unless you've just got your little, like in the last year, because then I think it takes effort on our part to establish the relationship)