As everyone is sharing his or her timeline and processing, I want to share mine too after getting letter in Feb regarding my sibling in which according to CHC ND he's not dependent, and my parents responded with explaination within stipulated 30 days. I didn't heard anything from them as case was filed in may 2008. I think as they gave only 30 days limit , CHC ND should also respond or take an action after those thirty days. It's really hard to understand why they provide time limit to us not themselves.