Well I have had a partly sucessful unlock of my XP1900. I have 6, 6.5, 11, 11.5, 12, 12.5, 13- havent tested 14 and 15 and dont know if they will work in any event. I dont have 7, 7.5, 8, 8.5, 9, 9.5, 10, 10.5 but dont see myself ever using most of those anyway.
I am somewhat tempted to try...