[jpwhre]

0.37.0000 is old stock/locked spl and unlocked is 0.37.COMEX and i too had this relock issue after going back to stock. took some time to realize that the updated stock rom put spl to 0.40.0000 which it is locked to updated spl. and yes the unlocker hardspl from comex will unlock 0.40.0000 to 0.37.COMEX. put it in bootloader and check.

EDIT: it wont ALWAYS lock it to .40 though maybe 1 in 5 times.