C6748 SPI Slave boot op-code synch fails

I'm trying to boot up a C6748 as a slave on the SPI1 bus.  I can send the transmit start word synchronization and I get the receive start word synchronization.  The ping op-code synch also works.  I send the ping and recieve the correct reply.  I send a random word and get the same random word back.  I send 0x00000001 and I get that back.  I send a 0x00000002 and then I get that back.  At this point I believe ping op-code synch should be complete and I can start op-code synchronization.  The first op-code in my AIS file is 0x5853590D.  I send this in 16 bit little endian format (first 0x590D then 0x5853) just like all of the values in the op-code synchronization.  It never works.  I try this many times in a row but I either get back 0x0000 0x0000 or I get back 0x5253 0x000.  The response alternates between those.  I've stepped slowly through the code so there are literally seconds between each 8 bits sent over the bus; the SWS and POS work but the op-code synch fails.  I don't know what is going wrong or what to try at this point.