Uncommon Problem with my psp please help!

I have had my psp for about a year now and I started using custom filmwares about 5 months ago. The problem with my psp is that it does not function well. When I turn it on, sometimes it acts as if its bricked, meaning the light stays on and no menu pops up or anything. Other times it comes on and it works like usual, sometimes after it works and I try to enter a folder like a system folder or a game folder, it will do the little load thing in the corner for like a half second then nothing happens, and ill keep tryin it and itll keep doing the same thing, so i just keep rebooting my psp until it works. The problem im having with it now is that i have final fantasy 9 and some other games on the 1gb memory stick and every time i make a save file and try to exit the game, either by using the "home" button or by holding the power button, it always freezes and so when i try to load the game it says no save file available. So I tried downloading a save file into the folder from a friends psp and still it acts as if there is no save file even though the save file i copied is in the proper format, even the cso file games i have don't work because when i try to save a file nothing happens but i can still press the home button. I know this is long but I have one last problem. I thought that there was something wrong with the 1gb memory stick so I bought a 4gb memory stick and I still get the same problems, only I cant play cso games on the 4gb memory stick. If any one has the time please I really need help. Thank you!

First off.
I do this all too often.
Do not reference ISO/CSO(s) in the DCEmu forums.
Someone is probably going to tell me "It's legal and not piracy".
But it's in the rules, so live it.

The problems with your PSP sound idstorage related.
I would recommend getting Chilly Willie's Keycleaner and check your unit using it.

If your keys checkout fine.
You should reinstall your firmware.