when you flash any non fiasco image (e.g. kernel) with flasher-3.5 (or 0xFFFF) via usb, then NOLO automatically remove SW version string from CAL.

osso-product-info reading SW version string from CAL and parse it into OSSO_PRODUCT_* variables. If version is missing, it will use '<unknown>'.

So... now you know how this can happen.

Fix is easy, just set correct SW version string into CAL and reboot device. You can use 0xFFFF via usb mode (flasher-3.5 does support it *only* when you do full reflash) or via osso-product-info on device.

PR 1.3.1 Global SW version string is "RX-51_2009SE_21.2011.38-1_PR_MR0"

with 0xFFFF via usb:
$ 0xFFFF -S "RX-51_2009SE_21.2011.38-1_PR_MR0"

with osso-product-info on device:
$ osso-product-info -s OSSO_VERSION="RX-51_2009SE_21.2011.38-1_PR_MR0"