Bug is still there but pb is solved, simply use oepn('file', 'U')
see outputs :

fichin=open('test.txt','U')
===>
(2, 5, 0, 'final', 0)
2007-09-12 08:00:43
(5000000, 9.312000036239624)
(10000000, 22.312000036239624)
(15000000, 35.094000101089478)
(20000000, 47.812000036239624)
(25000000, 60.562000036239624)
(30000000, 73.265000104904175)
(35000000, 85.953000068664551)
(40000000, 98.672000169754028)
(45000000, 111.35900020599365)
(50000000, 123.98400020599365)
(55000000, 136.625)
(60000000, 149.26500010490417)
(65000000, 161.9060001373291)
(70000000, 174.625)
(75000000, 187.29700016975403)
(80000000, 199.89000010490417)
(85000000, 212.5310001373291)
('total lines read ', 85014960)
212.562000036

now with
fichin=open('test.txt')
or
fichin=open('test.txt','r')
===>

(2, 5, 0, 'final', 0)
2007-09-12 08:04:48
(5000000, 3.187999963760376)
(10000000, 6.3440001010894775)
(15000000, 9.4690001010894775)
(20000000, 12.594000101089478)
(25000000, 15.719000101089478)
(30000000, 18.844000101089478)
(35000000, 21.969000101089478)
(40000000, 25.094000101089478)
(45000000, 28.219000101089478)
(50000000, 31.344000101089478)
(55000000, 34.469000101089478)
(60000000, 37.594000101089478)
* 62410138                                                           
62410139 *
* 62414887                                                           
62414888 *
* 62415540                                                           
62415541 *
* 62420289                                                           
62420290 *
* 62420942                                                           
62420943 *
* 62421595                                                           
62421596 *
* 62422248                                                           
62422249 *
* 62422901                                                           
62422902 *
* 62427650                                                           
62427651 *
* 62428303                                                           
62428304 *
(65000000, 40.75)
(70000000, 43.953000068664551)
(75000000, 47.125)
(80000000, 50.328000068664551)
(85000000, 53.516000032424927)
('total lines read ', 85014950)
53.5160000324

best
Richard