Sharepoint web analytics does not show any data

Question

We installed Sharepoint Web Analytics some days ago (separated application pool).

Installation completed successfully.

Search works fine and returns expected results.

But reports still don't show any data :

Data Last Updated: 03.06.2014 02:00:23 There is no data available for this report. Here are some possible reasons: (1) Web Analytics has not been enabled long enough to generate data; (2) There is insufficient data to generate this report; (3) Data logging required for this report might not be enabled; (4) Data aggregation might not be enabled at the level required for this report.

What I tried :

• connect to website using different users (admin user included) and different browsers
• checked that needed services on server are started (especially analytics services)
• restart services Web Analytics Data Processing Service and Web Analytics Web Service
• checked that all services applications are started (WSS_UsageApplication status was stopped so I started it using Sharepoint 2010 Management Shell)
• checked service application associations (especially if Analytics Service Application Proxy is checked)
• manual execution of jobs (Web Analytics Trigger Workflows Timer Job, Microsoft SharePoint Foundation Usage Data Import, Microsoft SharePoint Foundation Usage Data Processing)
• manual start of incremental crawling
• IIS restart
• virtual machine reboot
• checked scope of data logging (especially if Enable usage data collection and Enable health data collection are checked)
• checked that the .usage file are generated correctly on the disk
• checked in the Logging database (WSS_UsageApplication) that the RequestUsage view contains data collected from the .usage files
• checked that data is successfully extracted from the logging database into the staging database (LastLoggingExtractionTime)
• checked that data was successfully copied from the staging database to the reporting database (LastDataCopyTime)
• checked on the website side that Advanced Web Analytics feature is Active
• granted ROOT\SPAppPool full control on the Web Analytics Service Application
• recreate web analytics application
• cleaned sharepoint cache configuration (deleted all .xml files from C:\ProgramData\Microsoft\SharePoint\Config\ and reinitialize cache.ini to 1)
• cleaned the drive where .usage file are generated so the message "Drives are running out of free space. Available drive space is less than twice the value of physical memory." does not appear anymore in ULS logs
• added ROOT\SPAppPool user to the Performance Log Users group on the local machine
• added ROOT\SPAppPool user to the Farm Admin group
• added dbowner permission for user ROOT\SPAppPool on WSS_UsageApplication and Sharepoint_Config databases
• install patch 2204024 (was already installed)
• manual execution of procedures in the staging and reporting databases (proc_DefragmentIndices, proc_UpdateStatistics, proc_WA_CleanFloatingFeedbackData, proc_WA_DeleteInvalidAdjacentHierarchyData, proc_WA_DeleteInvalidFactData, proc_WA_DeleteInvalidInventoryData in the reporting database and proc_DefragmentIndices, proc_UpdateStatistics, proc_WA_EnsureServiceBrokerEnabled in the staging database)
• checked that Windows service Sharepoint 2010 Timer is started
• checked for any message in ULS logs that could help...

All appears to work fine but I can't see any data in the reports.

Anything else I can try ?

EDIT 14 aug 2014:

Inventory data is collected successfully and I can see the related reports. Traffic and Search data still empty :