As said in title. Web page opens new tab (some Javascript action possibly) and when i close this tab using Ctrl+W or close button, it switch to next tab, not to previous one where i was. It is very annoying when it happens often, like in this case when page opens advertisements. I would just Ctrl+W to close advertising app and return back where i was, but no it always switch me to the next tab, not requested.
This behavior can be fixed by going to Falkon/Preferences/Tabs/Activate last tab when closing active tab It makes sense to have this option enabled by default.