Suspicious pointer assignment

[wallace]

Code:

TYPE two3tree
  root as two3node ptr
  size as integer
  depth as integer
  AddNode as Sub(value as integer)
END TYPE

SUB AddNode(value as integer)
  If this.root = 0 then
    this.root = NewTwo3Node(value)
  else
    dim p as Two3Node ptr
    p = this.root
  end if
  this.size = this.size + 1
END SUB

NewTwo3Node returns a Two3Node ptr but that like gives me an Implicit conversion warning and p = this.root gives me the suspicious pointer assignement warning. What's going on?