no internet connection after backup

[kultex]

I am using TCL on a Fujitsu Futro A210 (Geode LX800) with 89 MB of Ram  - works realy nice. After installing all apps, I changed the wallpaper (the only thing I do) - to have this permanent, its needed, to backup.
After backup, there is no more internetconnection - nither with sudo ifconfig eth0 up nore with netcardconfig - I can do what I want there is always no lease
When I restore, everything works fine again?

Do you have any idea?