When authoring a Silverlight LOB application (think Outlook) with Child windows, the child windows are are mere 'fakes'. They don't get their own taskbar item, hence CTRL-TAB does not work, only modal display possible etc...
Compare that to a typical LOB application like Outlook where you can open a contact besides a message and so forth. For a power-user, the Silverlight equivalent lacks in usability.
Am I the only one bugged by this? :) How do you guys solve this?