Hey, this happened to me today in school. I was messing around on my psp (which is 2.0 upgraded from 1.5) and i wanted to downgrade as i had some homebrew i wished to play. I forgot about the downgrade method and fiddled around with it a bit. i looked in the 'games' section and tried opening the 1.5 downgrade thing, but it said something about it already being 1.5.
so i gave up on that and my friend wanted to show me some pictures he had, so he was gonna send them to my psp. i went into photo and a black screen appeared with random white text. I forgot that the downgrade method required something to do with the photo category.
It froze my psp at the black screen so i restarted it by taking out the battery. i did it again and it froze again, so i took out the battery again. I then gave my psp to my friend who wanted to play liberty city ctories, and it warned him he needed 2.0 to run it. I looked in system info- and the psp was 1.0... WTF!!!!!
the web browser... it was all still there. i didnt get a chance to try anything out- so it may not work if you go into them. but they were there!!!
I left my psp in my school locker so ill bring it home tomorrow and take some pictrues and tlel you more about it. but this is weird!