Strange python script behaviour

[Łukasz]

Hi,
I have a problem with one of my python scripts. When I run this script
from command line it works correctly, but if I set up cron to run this
script on specified hour it works for a while and then "[Errno 32]
Broken pipe" error occures (always).

The strangest thing is that if I change command in CRON

from
python /home/xxx/script.py
to
python /home/xxx/script.py  > /tmp/script.log 2>&1

the script always works correctly!!!

The question is WHY? Any ideas?