mixed up icon-application connection

[mike <info mykey de>]

Hi

Some of the icons on my desktop are connected with the application
kuickshow for some reason and will not call nautilus any more - so when
I want to call my home directory I just get an error instead. I
uninstalled Kuickshow and everything works fine again .. until I
reinstall it - then things are mixed-up again. 
How can I change this back to normal ?

Thanks for your help
mike