when you right click on an icon in kfm and select open-with you get a window that allows you to type in a command or use the menu browser to select and app to run. When you click the browser you will receive a list of groups. However NO applications are listed in those groups. It just lists "This group is empty" I've checked with kde's BTS and it does not appear there - As well when compiled from tgz's it works ok.
I too am experiencing this problem and would be able to provide more information if requested. Thank you.
this is fixed in an upcoming errata release.