With Deskbar-Applet 2.21.90 the often requested Button UI that was already part in 2.18 returned. When you use this UI the results will be attached to the panel. Nevertheless, the window UI is still the default one.
In addition, Deskbar-Applet now recognizes when you change your peferred browser and activates the appropriate modules for you. E.g. when you were using Web History and Web Bookmarks for Mozilla before changing the preferred browser to Epiphany, Web History and Web Bookmarks for Epiphany will be enabled and the Mozilla modules disabled.
Last but not least, when Beagle returns more than 20 results, a match will appear that opens beagle-search to display all available results.
So download and install the latest version and report bugs you encounter to GNOME Bugzilla.