Off Line Message issue Windows ok Linux dont work OpenSim 0.7.0.2

I have a strange issue and the only difference is the operating system in which both run.
Premises:
All versions of apache mysql xoopensim are the same on both servers
All settings (.ini) are the same on both servers.

The problem:
Client is login in linux and sending IM to offline user

Hippo say System: User is not logged in. Message not saved
(but is not true... in database is the message)

Client is login in windows sending IM to a offline user

Hippo say System: User is not logged in. Message saved.

in both cases the message is really saved perfectly in table of xoopensim database.


When offline avatar login in retrieve msg from database I see in console in linux or windows the same message

[OFFLINE MESSAGING]: Retrieving stored messages for 5fxxxxxxxxx (uuid of avatar login in)

An then the data of table xxxxx_xoopensim_offline_message is deleted for the uuid of this avatar in both cases too, linux and windows.

Resumed: in windows work all ok.
In linux message is saved but to the client say not saved
when avatar offline login in have nothing...
but delete messages from table.

Im lost. I compare tables, sentences in php in both cases all is the same in Linux as in windows... but in linux fail.

Other difference when user login in linux or windows is that login in linux have a red error in console

[LLCLIENTVIEW]: Caught exception while processing OpenMetaverse.Packets.RetrieveInstantMessagesPacketSystem.NullReferenceException: Object reference not set to an instance of an object
at OpenSim.Region.CoreModules.Avatar.InstantMessage.OfflineMessageModule.RetrieveInstantMessages (IClientAPI client) [0x00000]
at OpenSim.Region.ClientStack.LindenUDP.LLClientView.HandleRetrieveInstantMessages (IClientAPI sender, OpenMetaverse.Packets.Packet Pack) [0x00000]
at OpenSim.Region.ClientStack.LindenUDP.LLClientView.ProcessSpecificPacketAsync (System.Object state) [0x00000]

In windows have not this error in console.

Please, ideas are welcome I am really lost. I dont know now in what direcction continue searching.

Regards