Problem with InetAddress.getLocalHost() on Java 7

[Paul Taylor]

It works okay for me but for a particular customer 
InetAddress.getLocalHost() is failing with Java 7 although it works okay 
with Java 6 with the following exception

java.net.UnknownHostException: rupert: rupert: nodename nor servname 
provided, or not known
     at java.net.InetAddress.getLocalHost(InetAddress.java:1466)
Caused by: java.net.UnknownHostException: rupert: nodename nor servname 
provided, or not known
     at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
     at java.net.InetAddress$1.lookupAllHostAddr(InetAddress.java:894)
     at 
java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1286)
     at java.net.InetAddress.getLocalHost(InetAddress.java:1462)

Is this by design ?

Paul