Strange blink pattern when trying to install 1.2 image

[lightcycle]

I'm trying to install the 1.2 image on a Bubba 2 to be able to update to a more recent Debian, but I'm having problems installing the image. I'm installing from a USB stick that could successfully install the 2.0 image when I tried. I unzipped the contents of the zip with the image to the USB stick, opened the install folder and copied the install.itb file to 8313E21.itb (is this right?), and still can't get it to work. The led flashes in the quick "install" fashion for about 20 minutes, it then switches to a weird pattern I cannot find in the manual. The led is on 2-3 seconds, then it blinks 7 times at 1Hz, then the cycle repeats. I left it for about 20 minutes more, nothing happened and I could not hear any HDD activity. I tried restarting it, and the weird blink pattern returns. The Bubba makes no DHCP requests at this point. Does anyone know what the blinking pattern suggests, or have any hints how to install the 1.2 image?

[jonj1]

I haven't had to use the 8313E21.itb file myself as mine is an older bubba2, but the procedure is likely this:

unzip b2-install-1.2.zip to USB pen drive
unzip just 8313E21.itb from installer v. 2.0
copy 8313E21.itb to new 'install' folder on the pen drive (without renaming)
proceed to re-install bubba...

[Ubi]

and set the partition on the usb drive to bootable. sometimes this seems to be important