Error confirmed for this python:
Python 3.0a1 (py3k, Sep 10 2007, 22:45:51)
[GCC 4.1.2 20061115 (prerelease) (Debian 4.1.1-21)] on linux2


See this:
stefan@nx6310:~$ python2.4 large_io.py
(2, 4, 4, 'final', 0)
2007-09-10 21:41:52
(5000000, 14.321661949157715)
(10000000, 30.311280965805054)
(15000000, 45.24985408782959)
(20000000, 59.537726879119873)
(25000000, 74.075110912322998)
(30000000, 87.76087498664856)
(35000000, 104.54858303070068)
(40000000, 121.84645009040833)
(45000000, 137.88236308097839)
(50000000, 155.42996501922607)
(55000000, 171.81011009216309)
(60000000, 188.44834208488464)
(65000000, 204.46978211402893)
(70000000, 218.81346702575684)
(75000000, 232.86778998374939)
(80000000, 246.6789391040802)
(85000000, 260.89796900749207)
('total lines written ', 85014960)
(85014960, 260.94281101226807)
**************************************************
(5000000, 14.598887920379639)
(10000000, 29.428265810012817)
(15000000, 44.457981824874878)
(20000000, 60.351485967636108)
(25000000, 79.3228759765625)
(30000000, 94.667810916900635)
(35000000, 110.35149884223938)
(40000000, 126.19746398925781)
(45000000, 141.83787989616394)
(50000000, 157.46236801147461)
(55000000, 173.10227298736572)
(60000000, 188.19510197639465)
(65000000, 197.369295835495)
(70000000, 206.41998481750488)
(75000000, 215.53365993499756)
(80000000, 224.55904102325439)
(85000000, 233.75891900062561)
('total lines read ', 85014960)
494.727725029
stefan@nx6310:~$ python3.0 large_io.py
(3, 0, 0, 'alpha', 1)
2007-09-10 21:50:53
5000000 194.725461006



Tasks: 144 total,   3 running, 141 sleeping,   0 stopped,   0 zombie
Cpu(s): 50.2%us,  1.3%sy,  0.0%ni, 48.3%id,  0.0%wa,  0.2%hi,  0.0%si, 
0.0%st
Mem:   1026804k total,   846416k used,   180388k free,     7952k buffers
Swap:  1028152k total,    66576k used,   961576k free,   679032k cached

PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
28778 stefan    25   0  7800 3552 1596 R  100  0.3   6:01.48 python3.0