com FAQ : access questions : shell : crontab problems?
Shell accounts do have enabled crontab. Crontab may hava a strange behaviour that you may submit a new one but you can not edit it any more with crontab -e. The problem lays in VIM editor secure temporary file handling. There are two solutions: 1. use another editor for crontab. $ export EDITOR=pico $ crontab -e 2.