Digital BW, The Print

Ok I know this has come up before but I think I have tried everything.  I made the 
mistake of attempting to swap the MK cartridge for the PK cartridge in my 2100.  And 
guess what - jobs stopped.  I have added back the MK cartridge and deleted the 
printer, put in the PK cartidge and added the printer.  I have turned the printer off and 
deleted the printer, turned it back on and then swapped the cartridges and readded it.  
I have Print Center Repair about 10 times.  I must be doing something in the wrong 
order....help!

Cheers

Steve