"Grisoft announces the end of support for AVG version 6.0 effective on December 31, 2004 for technical reasons. This version has been available since 1999. Its structure does not allow for further improvements planned for version 7 nor improvements in detection techniques expected to come in the future."
AVG is discussed in Schadenfroh's review at
http://www.schadentech.com/Reviews/Antivirus/antivirus_roundup.htm
I would like to stress that although AVG 6.0 will no longer be offered, they will be offering a new AVG Free Edition.