CPM3.SYS weirdness?

Hello list, I'm attempting to bring up CP/M Plus on one of my Z80 computers by running CPMLDR.COM from CP/M 2.2. It crashes immediately after CPMLDR.COM jumps to CPM3.SYS (I'm sure this isn't surprising). I'm looking at the memory dumps and comparing them to the original file. It appears for every 128 byte block, the order is backwards. I.e. if I look at five 128 byte blocks on my PC they appear in the Z80's memory to be as 5, 4, 3, 2 and 1. Not the 'correct' way. Is this normal or have I somehow botched the de-blocking algorithm on CP/M 2.2? Or, are there any known pitfalls or incompatibilities between the default de-blocking algorithm on CP/M 2.2 and the built in functions in CP/M Plus? I have written my BIOS from scratch, based on the vanilla files distributed with CP/M Plus. I haven't used the CPM3ON2 distribution. Thanks, Alexis K.