IOException in link analysis with ndfs-based web db

[Pablo Mayrgundter]

Exception in thread "main" java.io.IOException: Could not obtain new
output block for file /db/linkstats.txt
        at 
net.nutch.ndfs.NDFSClient$NameNodeCaller.getNewOutputBlock(NDFSClient.java:907)

This file already exists, so perhaps it needs to be deleted first? 
Would appreciate any pointers.

Cheers,
Pablo