Thank you Terra for asking that question. I just signed up a few days ago and as a newbie have been also having problems with the D and A chords. My fingers are on the thicker side and I cant seem to find the sweet spot where Im not muting the strings below my fingers. Maybe Im not getting enough curve in my hand but then I think I over correct and my thumb is lost somewhere behind the neck and I feel my fingers hand and arm adjusting to a very uncomfortable position and feeling...and it still isnt the sweet spot. Think I will try the 2 finger method discussed...

Thank you everyone