Current 4.0.2 eeschema release generates a bad header in the PADS PCB netlist export.
I have submitted a bug & solution here for this
Until that fix is in the distribution, users can do the manual edit themselves in the Generate Netlist PADS PCB plugin.
Fix: edit the script file
netlist_form_pads-pcb.xsl
line 18, replace string *PADS-PCB* with !PADS-POWERPCB-V1-MILS!
With that change, if you have correctly mapped eeschema.footprints to PADS Parts, PADS ASCII Import will work ok.