The stages of the upgrade:

1. upgrading using update manager - everything looks ok untill the last reboot - NO NETWORK (not wired nor Wi-fi) 
2. Grate I have a laptop found a workaround (uninstalling network manager and getting connection using console ...) from this post. 
3. This is workaround and i don't like it. than I found posts saying upgrading BIOS version (Asus M2N-E) - so I've tried this was the end of my computer. even the BIOS not loading.
4. By a miracle the computer is under warranty (in IVORY) so after 5 days I got a new motherboard.
5. now downgrading to the working 8.04 Ubuntu version.
   
6. after a week this motherboard stopped working to.
7. another 4 days and one more  motherboard, and things start working again.
8. Installing the new Ubuntu 8.10 version with wicd and ... its working :-) !!!!!!!!!!!!!!