Ok, ive decided to take the plunge and upgrade my 1.0 Jap to 1.5 (fed up of all the 1.5 releases and other apps not working).
So I have the Jap 1.5 upgrade, its in my game/ folder in a folder called "firmware", but whenever i execute it i just get a black screen then it reboots to the psp menu.
I hoped it had worked, but still says 1.0.
AC adapter is plugged in. (tried it without too).
Only thing ive done recently is try Wab 2.5 version changer, and yes, ive set it back to 1.0.
If i try to launch the updater without a UMD in the drive i get Error: Could not start the game. 80020148