Have you tried this tip from the klok site?
http://klok.mcgraphix.com/klok/klok_1_5.htm
Some people have reported that there is an issue with installing the beta over an existing 1.0 installation which results in what seems like the entire project list going missing. It also seems that you cannot create any new projects. There appears to be an issue finding the data from the default data location which is easily solved.
If you go to the Preferences screen and click the button to choose a new data file folder you will be prompted with a directory browser. If you leave the default selected folder as is and click “ok”, it will start working.