Thanks for the tips. I just needed it to work that way so that the script can be run via cron without changing anything.

Anyway, changing it to behave differently wouldn't take more than a few seconds. I can live with that. I just really wanted to know why my program behaves that way and if there's something I can do about it. It's big script that talks to web applications, processes xml's, writes excel spreadsheets and sends emails etc. I didn't really have to ask a question from the beginning as most of the time google solves my problem. I just got stuck with this one and it bothers me that I was able to solve all my bigger problems before but quite clueless with this one.