Current dev keeps requiring update

Update status reports that the last dev is not the most recent, having "available update"

Update status pretends that this module dates 2010: 6.x-2.x-dev (2010-jui-11)
and that the newest version is 6.x-2.x-dev (2011-fév-25) - precisely the one which is uploaded

The info file is

name = Matrix Field
description = Defines field type for table with textfields.
package = CCK
core = 6.x
dependencies[] = content
; Information added by drupal.org packaging script on 2011-02-25
version = "6.x-2.x-dev"
core = "6.x"
project = "matrix"
datestamp = "1298619612"

Maybe a timestamp problem?