iPod Touch 1G Background not changeable?

Sry I didn't recognized that this was an english forum^^ (stupid...I know)

So I try to translate:

I can't changed the background of my iPod Touch (Lock-Screen), that means, I am able to go to Settings and set a new Background, but when I press "Save", there is no change! The same Background again and again....I'm getting very dizzy.....

My iPod is:
- 1G
-on firmware 2.2.1
-jailbreaked
-previously backuped (no change....problem still remains)

Can someone help me with my problem?

BTW: If someone could tell me how I get Summerboard or Customize on firmware 2.2.1 it would help a lot.....I would try to change background with those apps!

Don't use Customize, the version that is supposed to work for 2.2.1 is just a port from the 1.x versions and it doesn't work properly.

Download Winterboard, it's less graphically intuitive as Customize but gets the job done nonetheless. *NOTE* Winterboard does use alot of system resources though, so you can try using BossPaper if you choose to make the move to 3.0.