Must be 5.50 gen-a/b2 if not download this to update to the latest firmware
http://www.megaupload.com/?d=2Z8QKS2MMgs Pw Demo Download:
http://www.sendspace.com/file/2khko7Installation:
Goto Recovery menu and enable flash0 in USB mode
Click on VHS>ECT>(here)
Right click on version and goto properties
Untick read only and open up the txt
Delete all the information in the txt box and put in:
release:5.55:
build:3230,0,3,1,0:builder@vsh-build6
system:52556@release_555,0x05050510:
vsh6434@release_555,v52629@release_555,20090608:
target:1:WorldWide
once thats done save it and retick read only (make sure its ticked)
Restart your psp and go into recovery menu and click on configuration
scroll down and enable "use version.txt"
There ya go guys