Guys just asking why we should upgrade or downgrade PSP firmware.....

Because I saw ad to upgrade and downgrade PSP

1)Firmware 3.71 M33-2
2)Firmware 3.90 M33-3
3)Firmware 4.01 M33-3
4)Firmware 5.00 M33-4 (latest)

I understand if somebody want to upgrade their firmware because it latest ... but why to people downgrade their PSP firmware... I'm new ... so that's why I'm asking..

Hi...

I want to put wallpaper on my PSP but the picture "wallpaper" not full screen. So I need to edit the picture ... can anybody advise me on the size, resolution, height,...etc.

Another thing guys ... Can I just dump video file "mp4 or avi" directly to my PSP.... or do I have to convert it ....? If I have to convert to make it smaller what are the resolution, aspect ratio... etc... ?