Flex and fcs3 not playing well together

i havent woked on any as3 projects in a few months but now am getting back at it with a new project although now fcs3 and flex dont want to play well together like they used to.

first problem is when i have a movieclip in fcs3 linked to a AS3 class and put another movieclip inside it (in fcs3) and give it a variable name and try to declare it in the AS3 class

public class Puzzle1 extends MovieClip{
		public var myImg:MovieClip;

it gives me this error: 1151: A conflict exists with definition myImg in namespace internal.

my second problem is when i try to pass tat same Puzzle1 class to another class it wont let me

public var pGrid:PGrid = new PGrid(this);

it gives me this error: 1067: Implicit coercion of a value of type Class to an unrelated type game.p1:Puzzle1.
but if i pass it in as a MovieClip it works fine, this i know can not be right.

any ideas on what the problem could be?