System->Admin->Networking Change hostname trashes hosts file

System->Admin->Networking Change hostname trashes hosts file

I am using Ubuntu v6.06 (dapper). I have a large hosts file (over 5k entries, most pointing to 127.0.0.1) that I use to block unwanted sites.

When I used System->Admin->Networking to change my host name it took a long time to complete. Then I could no longer use sudo or any System->Admin menu items. If I run sudo (from the console) I get the error "sudo: unable to lookup Ubuntu via gethostbyname()" ("Ubuntu" is my new host name). Looking at the bad (after changing hostname) and good (before changing hostname) /etc/hosts files I see:

-begin bad hosts file---------------------------------------------------------------------------------------------------
# localhost: Needs to stay like this to work -------------------
127.0.0.1 localhost pop3.norton.antivirus pop3.spa.norton.antivirus 07.moosq.com 1.httpdads.com 102.112.2o7.net 112.2o7.net 123banners.com 12greatsoft.biz 15.moosq.com 17greatsoft.biz 193.125.201.50 2.idsbi.com 203.geekpost.com 206.161.200.105 207-87-18-203.wsmg.digex.net 209.66.114.130 216.200.3.32 22469.com 2366.pinoycentral.com 239.255.255.250 247realmedia.com 2o7.net 3.adbrite.com 334es5s.com 3wisp.com 4.idsbi.com 64.124.45.181 66.250.130.194 66.40.16.131 85.spylog.com a.about.com a.as-eu.falkag.net a.boom.ro a.mktw.net a.tribalfusion.com a.tribalfusion.com a.websponsors.com a.youlllovethisdatingsite.com a1.interclick.com a1040.g.akamai.net a1066.g.akamai.net a207.p.f.qz3.net a3.suntimes.com a408.g.akamai.net aaafreexxx.com aavalue.com abc.com-yahoo.com ablt.com abril.ad.uol.com.br abscbn.spinbox.net Absolute.ONTWOHGFJ.COM acces-direct.net accipiter.speedera.net accipiter.speedera.net/sbc-images.adbureau.net/sbc accountservices.passport.net accusal.qwwx4d.com acesseattle.com actionsplash.com actuating.org acvspgbrpgsjr.adware-business.com acxiom.com ad.abcnews.com ad.aboutwebservices.com ad.adition.net ad.adlegend.com ad.admarketplace.net ad.adnetwork.com.br ad.adsmart.net ad.adtraffic.com ad.adtraq.com ad.adultcheck.com ad.advisor.com ad.aftonbladet.se ad.atlas.cz ad.au.doubleclick.net ad.bannerpoint.ru ad.be.doubleclick.net ad.blm.net ad.boardhost.com ad.ca.doubleclick.net ad.candybar.co.kr ad.ch.doubleclick.net ad.cn.doubleclick.net ad.crosswalk.com ad.de.doubleclick.net ad.deviantart.com ad.dialpad.com ad.dk.doubleclick.net ad.dogpile.com ad.doubleclick.com ad.doubleclick.net ad.doubleclick.net ad.erektor.ru ad.es.doubleclick.net ad.espn.starwave.com ad.fr.advertissimo.net ad.fr.doubleclick.net ad.free6.com ad.harmony-central.com ad.hinet.net ad.hk.doubleclick.net ad.horvitznewspapers.net ad.howstuffworks.com ad.img.yahoo.co.kr ad.inetfast.com ad.infoseek.com ad.it.doubleclick.net ad.itmedia.co.jp ad.iwin.com ad.jamster.com ad.jp.doubleclick.net ad.kimo.com.tw ad.kr.doubleclick.net ad.linkexc
 Ubuntu

# The following lines are desirable for IPv6 capable hosts
ff00::0 ip6-mcastprefix

#####################################################################
# The Hosts File Project http://hostsfile.mine.nu
# Global Advert Servers Blocklist - Personal Edition
#####################################################################
# Release 13/07/2006
# Servers Verified as up and running 04/03/2006 (by dns resolving)
# Updated sorted and maintained by Andrew Short (sh0rtie)
# Contact: <email address hidden>
######################################################################
# You must keep the below lines
######################################################################

#127.0.0.1 images.ibsys.com

#Daves Bad sites 070223
-end bad hosts file-----------------------------------------------------------------------------------------------------

-begin good hosts file---------------------------------------------------------------------------------------------------
# localhost: Needs to stay like this to work -------------------
127.0.0.1 localhost
127.0.1.1 davem-ubuntu

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts

#####################################################################
# The Hosts File Project http://hostsfile.mine.nu
# Global Advert Servers Blocklist - Personal Edition
#####################################################################
# Release 13/07/2006
# Servers Verified as up and running 04/03/2006 (by dns resolving)
# Updated sorted and maintained by Andrew Short (sh0rtie)
# Contact: <email address hidden>
######################################################################
# You must keep the below lines
127.0.0.1 pop3.norton.antivirus
127.0.0.1 pop3.spa.norton.antivirus
######################################################################

127.0.0.1 07.moosq.com
127.0.0.1 1.httpdads.com
127.0.0.1 102.112.2o7.net
127.0.0.1 112.2o7.net
127.0.0.1 123banners.com
127.0.0.1 12greatsoft.biz
............................continues for over 5K lines..........
-end good hosts file-----------------------------------------------------------------------------------------------------

Fortunately I had an old copy of my hosts file. I went into recovery mode and restored the file, edited it manually and all seems well.