Network folders stop working

[invantix]

Alfresco network folders stop working after a while. I see an exception in the logs:

java.lang.IllegalArgumentException: Invalid NetworkFile class
at org.alfresco.jlan.server.filesys.cache.FileStateLockManager.lockFile(FileStateLockManager.java:43)
at org.alfresco.jlan.smb.server.NTProtocolHandler.procLockingAndX(NTProtocolHandler.java:1955)
at org.alfresco.jlan.smb.server.NTProtocolHandler.runProtocol(NTProtocolHandler.java:284)
at org.alfresco.jlan.smb.server.SMBSrvSession.runHandler(SMBSrvSession.java:1377)
at org.alfresco.jlan.smb.server.SMBSrvSession.run(SMBSrvSession.java:1298)
at java.lang.Thread.run(Thread.java:619)

Any idea what could be going on here?

[joao_pereira]

I'm having the same problem here
I've installed alfresco portable as described here http://forums.alfresco.com/viewtopic.php?p=2175& to demo it.
I've updated to the following version:
Alfresco started (Community Network): Current version 2.9.0 (C_dev 779) schema 118 - Installed version 2.9.0 (B 683) schema 116

I'm able to connect (not allways) to the CIFS using a mapped drive to \\nameA\alfresco
but 1 second after I'm pleased with the explores crash and the following in my logs:

java.lang.IllegalArgumentException: Invalid NetworkFile class
        at org.alfresco.jlan.server.filesys.cache.FileStateLockManager.lockFile(FileStateLockManager.java:43)
        at org.alfresco.jlan.smb.server.NTProtocolHandler.procLockingAndX(NTProtocolHandler.java:1955)
        at org.alfresco.jlan.smb.server.NTProtocolHandler.runProtocol(NTProtocolHandler.java:284)
        at org.alfresco.jlan.smb.server.SMBSrvSession.runHandler(SMBSrvSession.java:1377)
        at org.alfresco.jlan.smb.server.SMBSrvSession.run(SMBSrvSession.java:1298)
        at java.lang.Thread.run(Thread.java:595)

[joao_pereira]

I've spent some hours around this issue and I cannot get any way out. please, someone can give me some hint here?

thanks

[torsten_e]

I have the same problem

[john]

I'm having the same problem:  Alfresco Community 2.1, running on Ubuntu 7.10 server, with Apache2 configured to serve the pages from behind an HTTPS gateway.  WebDAV works perfectly for a time - usually in the range of ~30 minutes - for any given user, before it stops allowing access and AccessDeniedExceptions start popping up in the logs.

Any suggestions at all?