I'm sure you've got to be right. It's so strange that it works sometimes. Now I've added to my crontab line a call to the user's .profile and it seems to be working!

Old user's crontab line:

* * * * * perl /home/user/data/code/copy.pl ftp3 >> /tmp/ftp3.log 2>&1
[download]

New user's crontab line:

* * * * * . ~/.profile; perl /home/user/data/code/copy.pl ftp3 >> /tmp
+/ftp3.log 2>&1
[download]

Well that lasted about a minute, timed out and back to errors from crontab