W52H on Fritz!Box 7360

[miroslav]

Hi,

I am trying to get W52H to work as a DECT handset on Fritz!Box 7360. I can register the handset, and it connects to the base on Fritz!Box and registers, but after that I get a message 'Initializing Data' on the handset, and whatever I try to do, it keeps saying 'Synchronizing, please try later'.


When I go to Info -> Handset, I get the following:
Model:
W52P
Hardware:
26.0.0.7
Handset Firmware:
26.50.0.20

I tried upgrading handset firmware to 26.73.0.10 using USB cable, using W52p-Flasher[4.11.0.1].exe but when I click on 'Upgrade' nothing happens (I am running Windows 7 as a guest OS inside VirtualBox on Ubuntu Linux).

Fritz!Box is 7360 running Fritz!OS 6.20.

Regards,
Miroslav