OK, there seems to be some confusion over the Jap PSP/UK Firmware issue, but if it doesn't change the X and O buttons back it might not really be worth it! That was my only thought about changing the ol' firmware in the first place.
If I was playing a UK game on a Jap PSP, running either Jap or UK firmware, are the X and O buttons only swapped in the PSP menus or does this affect the games as well?