Launch feedback issue

Hi I'm on kde in Fedora 12 and I have launch feedback / Task bar notification set. When I start firefox or thunderbird from plasma or from the kickoff menu I get a bouncing icon that runs till the timeout (30s). The only slightly strange thing in my setup is that the firefox command (icon settings/application) is set to firefox %u and that resolves to a script in (nfs mounted) /usr/local/bin. This is so I can launch different firefoxes depending on which system I'm on. I'd be grateful if anyone can suggest why the bouncing icon keeps going till timeout or can point me to some docs that explain how the launch feedback works. Thanks Roderick Johnstone