After setup the nice astroberry image and fine tuning of the system i recognised temporarily WLAN loss in a regular base.
Looking in the log files I got no explanations for this effect.
Searching in the web i found some information that the COUNTRY=PL setting could be the problem.
So I changed the COUNTRY language setting to DE which was set also in mein raspi-config settings.
After this was done the nasty temporarily WLAN loss incidences stopped.
so what exactly did you change in these 3 files?
1.xml style file, did not find anything related to country settings
2. uncommented country and set to DE, but since this is just an example file this doesn't really do anything...
3. set country to DE, but this seems to break my network connection alltogether.
so can you please elaborate what you actually changed?