Dialog 'Create WLAN connection in offline mode?' appears when trying to use already active WLAN connection

I am developing an application for Symbian which contains a kind of access point manager. It uses QNetworkConfigurationManager to find available network configurations and opens QNetworkSession using already active configuration (if there is any). This process should be transparent to the user. However, when phone is in offline mode system dialog 'Create WLAN connection in offline mode' appears. It is unneeded as WLAN connection is already created.

Steps to reproduce:
1. Set 'offline' profile on phone
2. Go to Settings -> Connectivity -> Wireless LAN
3. Connect to any available WLAN network
4. Start an example application (see attachment). Active connection is used without any question notes.
5. Close application and start it again.

Expected outcome: active connection is used, no question notes shown (as previously)
Actual outcome: dialog 'Create WLAN connection in offline mode?' is shown