12b36d5d_ebug_Preferences___FirebugWiki__Option
[Description] Previous Firebug UI placement within the browser (0-unknown, 1-in browser, 2-in a new window, 3-minimized [Valid Values] 0,1,2,3 [Default] 0 [UI Equivalents] Buttons on the right side of the panel bar. [Option] 
previousPlacement
Firebug Preferences - FirebugWiki