Ricardo,
I have a similar setup Server 2012, running Revit Server 2013, and I'm haveing the same problem opening or saving models. I get a slightly differnt error though.
2013-04-10 16:42:19,504 ERROR TID(11) LOGGER(Autodesk.Revit.RS.Service.Protected.Model.ModelServiceImplementation) MSG(BlockError: System.OverflowException: Arithmetic operation resulted in an overflow.
at System.Data.SQLite.SQLite3.GetBytes(SQLiteStatement stmt, Int32 index, Int32 nDataOffset, Byte[] bDest, Int32 nStart, Int32 nLength)
at System.Data.SQLite.SQLite3.GetValue(SQLiteStatement stmt, Int32 index, SQLiteType typ)
at Autodesk.Revit.RS.Core.Model.ModelStorage.ModelLocationSQLiteDbTable.parseOneRecord(SQLiteDataReader dataReader)
at Autodesk.Revit.RS.Core.Model.ModelStorage.ModelLocationSQLiteDbTable.readRecord(ModelIdentity modelIdentity)
at Autodesk.Revit.RS.Core.Model.ModelStorage.ModelStorageProvider.locateModel(ModelIdentity modelIdentity)
at Autodesk.Revit.RS.Service.Protected.Model.ModelServiceImplementation.LocateModel(ModelIdentity modelIdentity)
at Autodesk.Revit.RS.Service.Protected.Model.ModelServiceImplementation.CreatePermissions(ServiceModelSessionToken sessionToken, PermissionsFormatVersion permissionFormatVersion)
at IModelServiceProxyd68ce8001e454bb6a8a801c5f0a957b4.InvocationCreatePermissions_34.InvokeMethodOnTarget()
at Autodesk.Social.Core.Implementation.Logging.LoggingInterceptor.Intercept(IInvocation invocation))
2013-04-10 16:42:19,505 INFO TID(11) LOGGER(Autodesk.Revit.RS.Service.Protected.Model.ModelServiceImplementation) MSG(BlockEnd: Autodesk.Revit.RS.Service.Protected.Model.ModelServiceImplementation.CreatePermissions)
I'm hoping your solution will somehow point me in the right direction.