The client type is sent to the WM when activating a window. For a panel, it should be WNCK_CLIENT_TYPE_PAGER, but the default is WNCK_CLIENT_TYPE_APPLICATION. This is needed, because some WMs decide to ignore focus stealing requests from applications. See http://standards.freedesktop.org/wm-spec/wm-spec-1.3.html#id2731082
Created attachment 4741 Patch
Even though this bug was created a year earlier and had a patch attached, another bug got the attention and was eventually fixed in commit d296ca7. *** This bug has been marked as a duplicate of bug 10508 ***