Ok heres some more detail...
Code:
	case WM_TIMER:
		InvalidateRect(hwnd,NULL,TRUE);
		SetRect(&rect,pt[0][0].x,pt[0][0].y,pt[0][1].x,pt[0][1].y);
		int check;
		check = CheckHit(pt,iSnakeSize,rect);

		MoveSnake(pt,iDirect,iSnakeSize);
		
		if((check==0) | WallHit(pt[0] ))
		
		{
			KillTimer(hwnd,1);
			MessageBox(hwnd,szBuffer,szAppName,MB_OK|MB_ICONINFORMATION);
			iDirect = 4;


			NewGame(&bFoodOnScreen,&iDirect,&iSnakeSize,pt,&iScore);
		}
		
		return 0;
I break at MoveSnake;
Everythings normal;
Everything normal upto return 0;
"No source code available"
Breakpoint at switch (msg) of WndProc
Step Into;
Takes me to WM_PAINT:
Step Into : hdc = BeginPaint(hwnd,&ps);
Step Into again : I am returned back to switch(msg) (??) (The rest of the code of WM_PAINT is not executed)(??)
Step Into again : msg = 20;
Step Into : DefWindowProc();
Step Into again : At this time pt[0][0].x is -256