If you want the channel icons on your MythWeb and MythTV you can use the following information to do so. I dont know why this is not included in MythTV .20 but you can grab it via SVN
First install XMLTV
sudo apt-get install xmltv
Then you need to download and rename the perl script
wget http://svn.mythtv.org/trac/browser/trunk/mythtv/contrib/mkiconmap.pl?format=raw
mv mkiconmap.pl?format=raw mkiconmap.pl
Run the script, I had to do this twice before it would work properly
perl mkiconmap.pl
Once you have done this just import it into the Myth Database
mythfilldatabase –import-icon-map iconmap.xml –update-icon-map
