my psp is in 2.01 edition

my psp is in 2.01 edition.but now i haven't found any software to downdate it to 1.50 edition
but it's said that if i update the 2.01 edition to 2.50 edition first, then use the software which can downdate 2.50 edtion to 1.50 edition,so i can success
is it right??????
but can a psp be updated and downdated for twice???
has it any risks in doing that???????

my psp is in 2.01 edition someone is living in my heart 歌词 My birthday is in November fourth my love is in nocent 翻印 There is sth wrong in my computer That man is my lover in side surf in the internet is my favouret someone is living in my heart 是什么意思 In my opinion,nothing is impossible! the letter is from my sister,( )is working in Beijing