Thanks for the clue.
Obviously since I reinstalled I had a fresh .inc file so I commented some lines and got rid of "Overwriting previous address content"
and for the "Duplicate label ("R1"..." I found in the file P18F25J50.INC located in the \Microchip\MPASM Suite\ folder contained twice the following line in different sections line 1673 and 1733.
Code:
R1               EQU  H'0002'
Commenting either one of them didn't make a difference but commenting both got rid of the error.

I would really like to know why! (a bug in MPLAB?)

Mike