Cron keep creating/outputting empty files

Hi, I have a php based website up and running with no problems. but it's just that for some time now I'm having these cron files getting created and output in/to my root directory every minute, and I have to delete them manually every day or two! so you can imagine how ridiculous that is, haha. I spoke to my 1and1 hosting support but they weren't very helpful, and they suggested that I speak to my web developer to fix the prob by logging in to the server through ssh not ftp. I cant get hold of my developer now. I tried to log in to putty ssh as they advised but for some reason the putty didn't load properly. I'm sure you're familiar with the prob and have a fix for it so please let me know if you can help and how much you'll charge, and what specific details apart from the usual login details you'd want me to provide you.
many thx