windows OCS agent fail to report to server

Hi,

• I have installed the agent on numerous machines and some of them fail to report.
• The machines are standard laptops with windows 8.1 32bit and 64bit. 
• During the execution time the ocsinventory.exe process memory is getting to 250000 MB and the CPU is 50%.
• After several minutes the report fail with server error 504.

In the ocsinventory.log trace I see two strange lines:

INVENTORY => 65535 memory slot(s) found 

...

INVENTORY => Bogus summed Memory Slots, 2048 is too far from 2012 (keeping the last one)​

and

INVENTORY => Inventory changed since last run
    INVENTORY => Generating XML document with Device properties
    INVENTORY => XML Update 65535 Logical Drive(s)

and in SysInfo.log I see:

WMI GetMemorySlots: Trying to find Win32_PhysicalMemoryArray WMI objects...OK (65535 objects updated)

Any ideas?

INVENTORY => Inventory changed since last run
    INVENTORY => Generating XML document with Device properties
    INVENTORY => XML Update 65535 Logical Drive(s)
    INVENTORY => XML Update common Device properties
    INVENTORY => XML Update BIOS
    INVENTORY => XML Update 2 Input Device(s)
    INVENTORY => XML Update 0 System Port(s)
    INVENTORY => XML Update 7 System Controler(s)
    INVENTORY => XML Update 1 System Slot(s)
    INVENTORY => XML Update 1 Sound Device(s)
    INVENTORY => XML Update 1 Storage Peripheral(s)
    INVENTORY => XML Update 1 Logical Drive(s)
    INVENTORY => XML Update 0 Modem(s)
    INVENTORY => XML Update 3 Network Adapter(s)
    INVENTORY => XML Update 2 Video Adapter(s)
    INVENTORY => XML Update 1 Monitor(s)
    INVENTORY => XML Update 3 Printer(s)
    INVENTORY => XML Update 277 Software
    INVENTORY => XML Update 0 Registry Value(s)
    INVENTORY => XML Update Administrative Information(s)
    COM SERVER => Initializing cURL library for sendRequest
    COM SERVER => Using cURL with server authentication
    COM SERVER => Disabling cURL proxy support
    COM SERVER => Enabling cURL SSL server validation support using CA Bundle <cacert.pem>
    COM SERVER => HTTP Post response received <HTTP Status Code #504>
    COM SERVER => Cleaning cURL library
ERROR *** AGENT => Failed to send Inventory <HTTP Status Code #504>
AGENT => Unloading communication provider
AGENT => Unloading plug-in(s)
AGENT => Execution duration: 00:11:56.