I'm using the XFce 4.2 beta packages from os-cillation and whenever I check the option "Use startup notification" on the Item properties of any Launcher, the mouse cursor stays "busy" for about half a minute, even when the application has been already loaded. It happens for all Launchers in the panel.
The application you start has to support this feature as well. That means gtk2 applications will usually work, kde ones may work as well, but many other will not. The notification will time out after 30 seconds. Thanks, but there's nothing we can do about this.
Anyway, could the notification timeout be less than 30 seconds? I believe that the best choice would be just to turn startup notification off for launchers that launch non-gtk2 applications, but the regular user of Xfce won't probably be concerned about this difference and will think - like I did :) - that it was just a bug.
Just like you told me, startup notification is working for every gtk2 application I launch from the taskbar (I've turned it off for non-gtk2 applications) for the except of one of them: xfce-setting-show (which shows the same problem, i.e. the cursor stays busy until timeout). Could it be a bug in xfce-setting-show?