What is the point in downgrading to 1.5 FW

im a noob at this whole CFW buisiness but what really is the point in downgrading to 1.5
i had a phat psp at 3.8 then made a pandora's battery and upgraded to CFW 3.8 M33-5 which almost all of the things i downloaded didnt work
so i downgraded to 1.5 and now i just dont know what to do :-/
and what actually happens with the pandora's battery process?

ty

You can upgrade to CFW from 1.50.

so the reason to downgrade is to upgrade to a modified latest version?

why does half the stuff i use not work then X(

What stuff?

like the software that i got from the BrewPack Generator most of it just made my psp shutdown or just says game cannot be played or just shows up as corrupted

what fw u at? if its cfw which one? u might need to change some settings
and the brew pack gen sucks

like the software that i got from the BrewPack Generator most of it just made my psp shutdown or just says game cannot be played or just shows up as corrupted

I had that problem too. If a homebrew doesn't work in the
"GAME" folder move it to the "GAME150" folder.

If you still get nothing make sure you have
the 1.50 kernel for your CFW.

If and when they return, you'll find this guide very helpful: http://www.psp-hacks.com/forums/viewtopic.php?id=119276 (it's down right now, but bookmark it and check it after several days.)