Cannot get ST_STM32F469I_DISCOVERY loader.elf to load (program) QuadSPI Flash

I'm having problems getting the STM32F469I_DISCOVERY board specific  loader to work wrt the onboard QUAD spi flash memory.

I've have another project using the STM32F746 Discovery using 'identical' settings and it loads stuff into the QuadSPI flash without any problems (so I think I know what I need to do to get it working, as I have it working well for this board)

I do exacly the same thing with the STM32F469I_DISCOVERY and it does not work!

I've checked the memory_map.xml , the Flash_placement.xml, I've loaded the right board support stuff etc and set the right project settings etc. I've compared the two boards memory maps etc.

Everything programs fine if I set the load option to "No" in the program section of the flash_placement.xml , but it fails to program if I set it to "yes" (which is what I obviously need). It fails very early in the Erase phase of loading the application file.

If I put what I want in the main flash instead of the QUAD SPI Flash, the board specific loader works and all is fine. So its clearly something specific regarding its ability to erase/write the QUAD SPI flash.

I expect I'm doing something daft, like wrong addressses, but I've checked and checked and checked, so if it is me, I'm blind to it !!!

thanks,

Mark