Hi Klaus,
thanks for you prompt response.
Yes, each "secondary" panel covers the whole area. What differentiates one from the other is the info showed on each one and the way that info is displayed (ListView, WebView, Labels and other elements).
Mainly the app, at this stage, should read some info from a remote MySql DB and show it back to the user. It's a kind of "passive" read-only app not asking any activity on the user (just read the infos and forget..).
Due to its simplicity I tried the "one-activity-may panels" approach, but as already described the Designer ended up in pure chaos.
Umberto