Stuck on version 8.0.10211.204 (Portico)

[Leshem]

Had the same problem. By following another thread on this site, I managed to update my phone: http://forums.windowscentral.com/samsung-ativ-s/246521-update-any-ativ-s-gdr2-now.html
In this thread, start by opening the link for interop-unlocked the phone.
When reaching the state that you are interop-unlocked, repeat again the following steps:
?Open the Phone dialer (the built-in one) and dial ##634# to install the Diagnosis app (if you hadn't already). You can exit it afterward.
?Run the Interop Unlock Helper app and read the instructions, clicking Next until you get to Step 2.
?Click the button to generate the toast notification for your phone's Diagnosis app, then tap on the toast to open the hidden registry editor.

in the registry editor add according to the following:
[HKEY_LOCAL_MACHINE\System\Platform\DeviceTargetingInfo]
name:"PhoneMobileOperatorName"
value:"000-AT"
make sure you write exactly as above! [without the quotation marks]
Uncheck DWORD etc. and click on write. It should display OK
Restart your phone and manually check for updates. It will start downloading!

 

[Igor Mesaros]

My Nokia Lumia 920 is also stuck on 8.0.10211.204 and the performance is very bad, its freezing a lot, the gps is not working, battery drains in a day even if i don't use it.

I didn't find any solution how to update to at least GDR2 but I found nothing. Is there any solution for this?