When I turn my computer on I get heaps of errors from Okular saying that /tmp/kde-luke/* cannot be opened. I think it is doing this because I downloaded files from Firefox and opened them then closed firefox before closing the pdf files.

I have tried uninstalling a purging Okular deleting the applications stuff in my home directory but it is still obsessed with these files. The only way I have been able to stop these annoying pop ups is by having the application uninstalled or running a starup script that will create these files on boot.

Anybody got any better ideas on how to stop this annoyance?

Check the ownership of the /tmp/ directory and /tmp/kde-luke/. Is luke your user name? If the directory /tmp/kde-luke/ is not owned by you, it may be the problem.

There is no problem with the permissions, as you would know the files in /tmp are wiped on shutdown or boot and the problem is that Okular wants to check that these files exist for some stupid reason.