Indexing fails after 4.1.0_01 update

Hi

I have been running Jahia 4.1.0 on Linux with Postgresql for a site with 
a lot of MS Word documents.
I had added tm-extractors-0.4.jar into WEB-INF/lib to allow text 
extraction and full text indexing of office documents content and since 
then the full text search was working pretty fine.

I just upgraded this installation with the Jahia update jar to version 
4.1.0_01  (build 6070)
The upgrade process was successful, but since then I get the following 
error in the logs :

*** /usr/local/tomcat4/logs/catalina.out ***
5131432 [Background content indexing] ERROR - Error while optimizing index
java.lang.IndexOutOfBoundsException: Index: 109, Size: 36
       at java.util.ArrayList.RangeCheck(ArrayList.java:507)
       at java.util.ArrayList.get(ArrayList.java:324)
       at org.apache.lucene.index.FieldInfos.fieldInfo(FieldInfos.java:155)
       at org.apache.lucene.index.FieldsReader.doc(FieldsReader.java:66)
       at 
org.apache.lucene.index.SegmentReader.document(SegmentReader.java:237)
       at 
org.apache.lucene.index.SegmentMerger.mergeFields(SegmentMerger.java:185)
       at 
org.apache.lucene.index.SegmentMerger.merge(SegmentMerger.java:92)
       at 
org.apache.lucene.index.IndexWriter.mergeSegments(IndexWriter.java:487)
       at 
org.apache.lucene.index.IndexWriter.optimize(IndexWriter.java:366)
       at 
org.jahia.services.search.JahiaSearchBaseService.optimizeIndex(JahiaSearchBaseService.java:1019) 

       at 
org.jahia.services.search.JahiaSearchBaseService.optimizeAllIndexes(JahiaSearchBaseService.java:1265) 

       at 
org.jahia.services.search.JahiaSearchBaseService.run(JahiaSearchBaseService.java:1228) 

       at java.lang.Thread.run(Thread.java:534)

I have a done a full re-indexing of the site, and still have the same 
problem
(actually I repeadly get the following :
1778065 [Background content indexing]  INFO - Finished processing 5 
indexing orders in 0ms.
1778092 [JahiaQuartzScheduler_Worker-1] DEBUG - Indexing field container 
definition name:boxcontainermain_1
1778131 [JahiaQuartzScheduler_Worker-1] DEBUG - Indexing field container 
definition name:boxcontainermain_1
1778170 [JahiaQuartzScheduler_Worker-1] DEBUG - Indexing field container 
definition name:boxcontainermain_1
1778210 [JahiaQuartzScheduler_Worker-1] DEBUG - Indexing field container 
definition name:boxcontainermain_1
1778230 [JahiaQuartzScheduler_Worker-1] DEBUG - loading field: id=1225 
loadVersion=[[workflowState=1 versionID=1119417185 languages=shared]]
1778230 [JahiaQuartzScheduler_Worker-1] DEBUG - Making JahiaField facade 
for field 1225
1778230 [JahiaQuartzScheduler_Worker-1] DEBUG - fieldType: 20 classe: 
org.jahia.data.fields.JahiaSmallTextSharedLangField
1778230 [JahiaQuartzScheduler_Worker-1] DEBUG - Returning JahiaField 
facade for field 1225 using language code=shared
1778230 [JahiaQuartzScheduler_Worker-1] DEBUG - Warning, no ParamBean 
found in thread context, using user siteID to resolve administrator 
group lookup ! Possible false permissions !
1778230 [JahiaQuartzScheduler_Worker-1] DEBUG - loading field: id=1225 
loadVersion=[[workflowState=1 versionID=1119417185 languages=shared]
1778230 [JahiaQuartzScheduler_Worker-1] DEBUG - Calling field specific load
1778252 [JahiaQuartzScheduler_Worker-1] DEBUG - Indexing field container 
definition name:boxcontainermain_1
1778264 [Background content indexing] DEBUG - Error adding doc from index
java.lang.IndexOutOfBoundsException: Index: 109, Size: 36
        at java.util.ArrayList.RangeCheck(ArrayList.java:507)
        at java.util.ArrayList.get(ArrayList.java:324)
        at org.apache.lucene.index.FieldInfos.fieldInfo(FieldInfos.java:155)
        at org.apache.lucene.index.FieldsReader.doc(FieldsReader.java:66)
        at 
org.apache.lucene.index.SegmentReader.document(SegmentReader.java:237)
        at 
org.apache.lucene.index.SegmentMerger.mergeFields(SegmentMerger.java:185)
        at 
org.apache.lucene.index.SegmentMerger.merge(SegmentMerger.java:92)
        at 
org.apache.lucene.index.IndexWriter.mergeSegments(IndexWriter.java:487)
        at 
org.apache.lucene.index.IndexWriter.optimize(IndexWriter.java:366)
        at 
org.apache.lucene.index.IndexWriter.addIndexes(IndexWriter.java:381)
        at 
org.jahia.services.search.JahiaSearchBaseService$SiteIndexer.storeInPersistance(JahiaSearchBaseService.java:1916)
        at 
org.jahia.services.search.JahiaSearchBaseService.run(JahiaSearchBaseService.java:1212)
        at java.lang.Thread.run(Thread.java:534)
)

What can be the cause for this ?

How is it possible to force a new filtering of the documents ?

Thanks for your support