Problem with artifact net.sf.json-lib:json-lib:jar:jdk15:2.3

[Richard Hierlmeier]

I have installed Archiva version 1.3.5 that mirrors 
http://uk.maven.org/maven2. It works quite well, however it can not 
resolve the artifact

   net.sf.json-lib:json-lib:jar:jdk15:2.3

The artifact is available at

   http://uk.maven.org/maven2/net/sf/json-lib/json-lib/2.3/

Even if I upload the artifact manually archiva does not find it.

What is so special with this artifact?

   Richard