TheEmulatorGuy (a.k.a. Teggles on Fanjita's IRC) just told me about something that I can't believe I never heard of.
To remove the 'corrupt data' icons on your PSP (1.50), rather than use a tool to do it, just rename your folders like this:
"Homebrew Name" --> "__SCE__Homebrew Name"
"Homebrew Name%" --> "%__SCE__Homebrew Name"
I've tested it out on my 1.50 and so far EVERYTHING works this way.
Once again, thanks to TheEmulatorGuy. Dunno who came up with this originally, but it's certainly easier than what I was doing before!
Edit: Upon further testing, it looks like you can just use this:
"Homebrew Name" --> "__SCEHomebrew Name"
"Homebrew Name%" --> "%__SCEHomebrew Name"