PIC16F1783: Erase algorithm incorrect

I have a Melabs U2 programmer. I have no problem programming a PIC16F886 and other microchip controllers of that type. I started a project planning to use a PIC16F1783 or a PIC16F1786. I tried to program the PIC1783 in circuit (like I successfully do with the PIC16F886) and get an error that says the erase algorithm is incorrect. I tried this on a programmer circuit (10 pin connector on PCB with a SMT SOIC28 socket and 5.0volt power and uses the U2 programmer) that I use to program chips prior to soldering onto a PCB. The 886 erases and programs fine. The 1783 gives me the same error - erase algorithm is incorrect.



I don't think I have a problem with my circuit or my programming PCB.


Is there difference in the erase algorithm for the PIC16F178x family or is there a problem with my parts?
If there is a difference with the algorithm, is there an upgrade to the U2 programmer I need to acquire?


I am using PBP 3.1.6.4 gold.