Test setup:
- Windows 2000 (french)
- Python 2.5 (reproducible with 2.4.2 and 2.4.4)

One python source file, test.py:
---
  import os
  print os.system("echo test")
---

Console output:
---
C:\test>test.py
test
0

C:\test>test.py > test.log
Descripteur non valide

C:\test>type test.log
0

C:\test>c:\python25\python test.py
test
0

C:\test>c:\python25\python test.py > test.log

C:\test>type test.log
test
0

C:\test>
---

The "Descripteur non valide" error would translate to "invalid file descriptor".

I would expect the 2nd call to perform the same way the 4th does.