i'm trying to install linux on my USB stick

During 2 weeks i've tried to install some distro like shinux, flonix, featherlinux and damn small linux, and I only succeed to boot with shinux.

But the 3 other distro don't work : everytime I try, the system correctly boot, i get the screen with penguin and « boot: » (here i've tried all i could, including nothing and failsafe), and everytime i get 4 or 5 lines that are normal, and after that, 15 or 20 lines with "cloop : error -3 or -5 uncompressing block xxx ". There are also many lines before with « xxx : not found »
and it ends with a "kernel panic : unable to mount root fs"

I don't understand why it dosn't work, i've tried on 2 different computers, and with 10 or 15 different versions and the problem is always the same.
How to get these distros working on my USB stick ???

Thank you very much of your answers.


P.S.: all apologies for my english and grammar... I'm a poor young french girl who doesn't understand anything !