What exactly is your problem?

To use AGPS, you need to be connected to internet (via WLAN or GPRS/UMTS).
AGPS will only fetch data to show an approximate location (few 100m) and load some satellite data (almanach) to provide faster satfix for GPS.

The reason for displaying Szadek is, as you already discovered, that it is the central part of your country. This is the first location chosen by Maps, when there is no valid GPS signal.