so i upgraded from 3.5 to 4.01 under debian this week, now i'm seeing this stuff going on.
I ran zmfixperms, and it still seems to keep happening! what can i do!?

2006-09-21 00:01:20,083 INFO [LmtpServer-3] [name=user@mail.domain.com;] ZimbraLmtpBackend - try again for message user@mail.domain.com: exception occurred
com.zimbra.cs.service.ServiceException: system failure: indexMessage caught IOException
at com.zimbra.cs.service.ServiceException.FAILURE(Ser viceException.java:174)
at com.zimbra.cs.index.Indexer.indexMessage(Indexer.j ava:161)
at com.zimbra.cs.mailbox.Message.reindex(Message.java :439)
at com.zimbra.cs.mailbox.Mailbox.endTransaction(Mailb ox.java:4338)
at com.zimbra.cs.mailbox.Mailbox.addMessageInternal(M ailbox.java:3297)
at com.zimbra.cs.mailbox.Mailbox.addMessage(Mailbox.j ava:3040)
at com.zimbra.cs.mailbox.Mailbox.addMessage(Mailbox.j ava:3024)
at com.zimbra.cs.filter.ZimbraMailAdapter.addMessage( ZimbraMailAdapter.java:325)
at com.zimbra.cs.filter.ZimbraMailAdapter.doDefaultFi ling(ZimbraMailAdapter.java:319)
at com.zimbra.cs.filter.RuleManager.applyRules(RuleMa nager.java:182)
at com.zimbra.cs.lmtpserver.ZimbraLmtpBackend.deliver MessageToLocalMailboxes(ZimbraLmtpBackend.java:308 )
at com.zimbra.cs.lmtpserver.ZimbraLmtpBackend.deliver (ZimbraLmtpBackend.java:122)
at com.zimbra.cs.lmtpserver.LmtpHandler.doDATA(LmtpHa ndler.java:420)
at com.zimbra.cs.lmtpserver.LmtpHandler.processComman d(LmtpHandler.java:197)
at com.zimbra.cs.tcpserver.ProtocolHandler.processCon nection(ProtocolHandler.java:231)
at com.zimbra.cs.tcpserver.ProtocolHandler.run(Protoc olHandler.java:198)
at EDU.oswego.cs.dl.util.concurrent.PooledExecutor$Wo rker.run(Unknown Source)
at java.lang.Thread.run(Thread.java:595)
Caused by: java.io.IOException: Could not create index /opt/zimbra/index/0/24/index/0 (directory already exists)
at com.zimbra.cs.index.MailboxIndex.openIndexWriter(M ailboxIndex.java:906)
at com.zimbra.cs.index.MailboxIndex.addDocument(Mailb oxIndex.java:349)
at com.zimbra.cs.index.Indexer.addDocument(Indexer.ja va:354)
at com.zimbra.cs.index.Indexer.addDocument(Indexer.ja va:324)
at com.zimbra.cs.index.Indexer.indexMessage(Indexer.j ava:156)
... 16 more
Caused by: java.io.IOException: Lock obtain timed out: Lock@/opt/zimbra/apache-tomcat-5.5.1...3de-write.lock
at org.apache.lucene.store.Lock.obtain(Lock.java:58)
at org.apache.lucene.index.IndexWriter.<init>(IndexWr iter.java:223)
at org.apache.lucene.index.IndexWriter.<init>(IndexWr iter.java:173)
at com.zimbra.cs.index.MailboxIndex.openIndexWriter(M ailboxIndex.java:887)
... 20 more
2006-09-21 00:01:20,084 INFO [LmtpServer-3] [] LmtpHandler - [192.168.1.9] 451 4.0.0 Temporary message delivery failure try again (DATA)
2006-09-21 00:02:10,861 INFO [IndexWritersSweeper] [] MailboxIndex - open index writers sweep: before=1, closed=1, after=0 (0ms)