key out of order

[Bogdan Kecman <bo...@alteray.com>]

This error started happening recently .. anyone have any ideas ?
It is nutch 0.7.2, the error appear after simple crawl instructions 
(50 threads, 2000 top site url's ... no other errors before it except few
"downloaded but cannot parse")

...

SEVERE error writing output:java.io.IOException: key out of order: 66248
after 66248
java.io.IOException: key out of order: 66248 after 66248
        at org.apache.nutch.io.MapFile$Writer.checkKey(MapFile.java:134)
        at org.apache.nutch.io.MapFile$Writer.append(MapFile.java:120)
        at org.apache.nutch.io.ArrayFile$Writer.append(ArrayFile.java:39)
        at
org.apache.nutch.fetcher.Fetcher$FetcherThread.outputPage(Fetcher.java:278)
        at
org.apache.nutch.fetcher.Fetcher$FetcherThread.handleFetch(Fetcher.java:261)
        at
org.apache.nutch.fetcher.Fetcher$FetcherThread.run(Fetcher.java:148)
Exception in thread "main" java.lang.RuntimeException: SEVERE error logged.
Exiting fetcher.
        at org.apache.nutch.fetcher.Fetcher.run(Fetcher.java:354)
        at org.apache.nutch.fetcher.Fetcher.main(Fetcher.java:488)
        at org.apache.nutch.tools.CrawlTool.main(CrawlTool.java:140)

...

This error appear for all 50 threads when it happen ...

Any help welcome (and nope, I do not want to move to 0.8 nor 0.9, I like
0.7.2 as it is the fastest one to crawl from single box)

Thanks in advance
b.