wuala nfs integration not working on my low end computer (pIII-800)

the volume is well mounted and i can browse the folders, but when i try to open a file a get this trace in wuala and no file :

at java.lang.Thread.run(Thread.java:619)
java.io.FileNotFoundException: /home/jave/wuala/Data/Local2/Large/8E0992E2AB725E2A999488DEAA66CFCE91F313D5
at com.wuala.domain.content.cache.data.b.b(Z:438)
at com.wuala.domain.content.cache.data.b.a(Z:384)
at ak.a.a(Z:96)
at com.wuala.service.model.item.obtained.h.a(Z:143)
at com.wuala.jlan.items.WualaNetworkFile.readFile(Z:85)
at com.wuala.jlan.DiskDriver.readFile(Z:313)
at org.alfresco.jlan.oncrpc.nfs.NFSServer.procRead(NFSServer.java:1524)
at org.alfresco.jlan.oncrpc.nfs.NFSServer.processRpc(NFSServer.java:518)
at org.alfresco.jlan.oncrpc.RpcRequestThreadPool$ThreadWorker.run(RpcRequestThreadPool.java:144)
at java.lang.Thread.run(Thread.java:619)

The same thing is working on my destkop computer (Core2Duo ...)

Both computer are running ubuntu-8.0.4