The Download Manager Tweak extension streamlines the current Firefox download manager. The extension allows the Firefox download manager to be opened in a separate window, the sidebar, or a tab. The extension also modifies the default appearance of the download manager to make it more concise and intuitive.  
 
a must-have extension for firefox that fixes one of the browser's minor, but annoying, inconsistencies.  
 
why would a tabbed browser force you to open downloads in a new window?!?!
HAHA
Frost: "why would a tabbed browser force you to open downloads in a new window?!?!"  
 
That made me laugh a geeky laugh... have some XP.