Years ago I worked with a boss who told me how much he cared. He said how important what I was doing was and he wanted to make sure that my contributions were noted. He said this frequently.
The problem was that it was lip service: when it came time to actually show that he cared, he inevitably failed.
The single most important thing he could have done to make me feel that he cared was to be at scheduled meetings on time. Instead, he would have other meetings run over my meeting time, often for hours at a time. As this happened time and time again, I could only reach one conclusion: he may care, but not much.
People understand that every so often you can run into issues, however, when these issues turn from a rarity to a regularity, they doubt your motives and your intent. Just like Joseph Grenny, Al Switzler, Kerry Patterson, and Ron McMillan talk about in Crucial Conversations, we make decisions in our minds based on a CPR pattern - is it content, pattern, or relationship. These continual broken promises escalate quickly from content to pattern and finally relationship.
When you commit to a meeting time with someone, keep that commitment. If you're habitually late, don't just leave 5 minutes early - that time frequently gets chewed up. As you're working to show that someone matters, block time out, be there early, and take something with you so that you're learning while you're waiting.