Similar issue here. I'm trying to force myself to stay in touch with local friends and distant relatives more often.I'm a terrible long distance friend and relative. If somebody is nearby, I will get together with them now and then(still not real often), and have a good time, and otherwise keep in somewhat contact. If somebody lives away and I seldom see them, I'm awful at keeping up with communication. Phone calls, texts, e-mail, facebook, I just start to fade away from doing it.
But then, once I see them, its almost like no time has passed and they still mean the same to me, I still love them.
Don't know if this trouble keeping in contact my people living away is more my INTP side than my INFP.