Hi Sebastian, hi Manfred,
updated lately to Z-Push 2.3.4 and saw that after you've updated the logging to have file and syslog there seems to be issues with file based logging and Windows Phone 8 device. This device does not send any username in GET Params, has no User in the Base64QueryString and so Z-Push according to code can only work with PHP_AUTH_USER. Unfortunately the logger gets only initialized with this PHP_AUTH_USER after the User Auth is being processed. But this is not covered by current lib/core/zlog.php . Means the User Name & Device ID never gets updated after initalize and authorization of user took place.
I've helped myself by adding some function in Write function but I'm sure that can be solved much more clever... Please have a look at it.
BTW... Please do a grep for DeviceInformaton in core/base/zpushdefs.php and core/wbxml/wbxmldefs.php ... and replace it with correct "spellchecked" word DeviceInformation - will save log from ugly automapping entries ;-)