I'm using Lubuntu 13.10. I'm really satisfied with LXDE except for the file manager PCManFM which not enough features. So I've decided to switch to dolphin which I've downloaded using synaptic. The thing now is: the only way to start dolphin is by typing its name into the terminal even though there's a (not responding) shortcut in the panel.
Got the same issue with Gnome and Konqueror if that helps...