No Software updates on serwer db

Hello everybody .
 
I need a tip: why DOES NOT ocs-ng agent update the software database ?  

OCS Inventory still shows eg. Java JRE ver. as in first report, and no updates that were made.

If a new monitor was connected, its enough to  "Run OCS inventory now "  from tray.

  
 The only way to update software db I've found is :
 - uninstall agent
 - Install OCS-NG-Windows-Agent-Setup.exe /S /LOCAL=C:\temp
 - manually import *.ocs  (manage - local import)

Workstations and server are in LAN, I think no firewall could block messages.
First install is always OK, data is send.

data at serwer: Sort by Last inventory : ca 50 PC's were inventoried in very few day.

none of them has updated Software

Server Parametres
FREQUENCY
Custom inventory frequency    Custom 1 day(s)

No additional plugins

Server
OS Name     : Linux x86_64
Kernel         : 3.2.0-4-amd64
RAM installed     : 7.82 Gio
PHP Version     : 5.4.45-0+deb7u2 (apache2handler)
Web Server     : Apache/2.2.22 (Debian)
Database Server    :(Debian) version 5.5.47-0+deb7u1-log

Workstations  
some Windows XP
most Windows 7 with regular (no admin) account