I think we need a better sidebar/webpanel mechanism. I am going to illustrate this opinion with two cases:

  1. launch firefox, show your bookmarks in the sidebar for instance typing ctrl-b and click on a bookmark to download it. Hide the webpanel typing again ctrl-b. Oh, well, that's not what you wanted to do, so you type ctrl-b a third time. The selection of your bookmark is gone because the document in the sidebar/webpanel was reloaded...
  2. launch Nvu, and open the Site Manager typing F9. Navigate in your site, and close the Site Manager to reopen it immediately. All your navigation is forgotten...

That's most certainly caused by the way the sidebar is displayed, through a <browser> element. I think it's time for a better option preserving your navigation history/selection/scroll in the sidebar. In the case of Nvu and its Site Manager, that's mandatory, I hear too many people complain about that.