unable to add launchers to panel or desktop

[techno-mole]

hello, im currently running the beta of intrepid ibex (kubuntu) (which i downloaded and burnt to cd)
ive found that i cant add launchers to the panel or the desktop.

if i open up the menu and go to applications, then select and app (say firefox for example) if i right click there is an option to add the launcher to either the desktop or the panel, if i select either one the result is a cog like icon appears, either on the desktop or panel.

if i then click the icon that gets created kate opens up and i get an error saying -

 " The file /home/username/firefox.desktop could not be loaded, as it was not possible to read from it.
Check if you have read access to this file. "

this as i have found applies to any application i try to create a launcher for.

cheers