Python 2.1 slower than 2.0

[Andreas Jung]

pystone.py with Python 2.0: ~3600 Pystones/sec
                Python 2.1: ~3000 Pystones/sec

Env. Linux i386, AMD-K2 300 MHz

Is there a reason why 2.1 runs significantly slower ?
Both Python versions were compiled with -g -O2 only.

Andreas