HI Peter
Try this...
Midi Interface
OUT
  to
 
  PE Midi
 IN
PE midi
OUT
 
 to
 
 M1 Midi
IN
M1 Midi
 OUT
 to Interface Midi
IN
While on M1
EDIT
 mode , it will show if the Patch is
SINGLE
 OR
DOUBLE.
On your PE,
 at Page
  "0"
 
 
 select
 
SINGLE
 or
DOUBLE
 accordingly to match the patch you are editing
 
Peace
Jonathan Yeo