file write performance drop between 2.5.60 and 2.5.70

[Vladimir Saveliev]

Hi

It looks like file write performance dropped somewhere between 2.5.60 and 
2.5.70.
Doing
time dd if=/dev/zero of=file bs=4096 count=60000

on a box with Xeon(TM) CPU 2.40GHz and 1gb of RAM
I get for ext2
2.5.60: 	real	1.42 sys 0.77
2.5.70: 	real 1.73 sys 1.23
for reiserfs
2.5.60: 	real 1.62 sys 1.56
2.5.70: 	real 1.90 sys 1.86

Any ideas of what could cause this drop?

Thanks,
vs