NPE when searching

gistfile1.txt

when I'm doing the query:

curl -XGET 'http://localhost:9200/tagindex/tag/_search?pretty=true&size=30&from=0' -d '
{ "query" : { "matchAll" : {} 
  } 
}'

I'm getting results ala:
[
 {
      "_index" : "tagindex",
      "_type" : "tag",
      "_id" : "twitellite",
      "_score" : 1.0, "_source" : {"lastId":42099340679847936,"queryInterval":25000}
    } ,
]

but when I increase the size=40 I'm getting the NPE:

2011-02-28 13:25:18,843 [elasticsearch[search]-pool-3-thread-1] DEBUG org.elasticsearch.action.search.type - [Hydro-Man] [tagindex][0], node[8Dv0T1EERT6JyH36o1MYtQ], [P], s[STARTED]: Failed to execute [org.elasticsearch.action.search.SearchRequest@7843f53]
    java.lang.NullPointerException
            at org.elasticsearch.search.fetch.FetchPhase.extractSource(FetchPhase.java:149)
            at org.elasticsearch.search.fetch.FetchPhase.execute(FetchPhase.java:82)
            at org.elasticsearch.search.SearchService.executeFetchPhase(SearchService.java:277)
            at org.elasticsearch.search.action.SearchServiceTransportAction.sendExecuteFetch(SearchServiceTransportAction.java:225)
            at org.elasticsearch.action.search.type.TransportSearchQueryAndFetchAction$AsyncAction.sendExecuteFirstPhase(TransportSearchQueryAndFetchAction.java:71)
            at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction.performFirstPhase(TransportSearchTypeAction.java:191)
            at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction.access$000(TransportSearchTypeAction.java:75)
            at org.elasticsearch.action.search.type.TransportSearchTypeAction$BaseAsyncAction$1.run(TransportSearchTypeAction.java:150)
            at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
            at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
            at java.lang.Thread.run(Thread.java:662)