Having problems with sidekick window taking focus?
1. Go to address bar and type about:config
2. Go to parameter browser.tabs.loadDivertedInBackground
3. Set its value as true
You will need to ignore the message that says this could void your warranty. You can also copy and paste 2) from here into the filter box and only that parameter will show. All you have to do is double click it to set to true. Close the window and your problems should be at an end.
Click the category Bug below to see related bugs.