tasksel-data not found in netinstall

["Juan Pablo Frias (Sendatel S.A)" <juanpfrias@sendatel.com.ar>]

Hi' I'm trying to build my own CD from a net install.iso Lenny 5.0.5 amd64
(http://cdimage.debian.org/debian-cd/5.0.6/amd64/iso-cd/debian-506-amd64-netinst.iso)
by running the command

./easy-build.sh NETINST amd64

Fail with:
dpkg-deb: error reading version number from file /home/jpfrias/borrar/tmp/:

Looking for the problem I've found this line in tool/update_task

TASKSEL_DEB=$MIRROR/`mawk '
   /^Package: tasksel-data$/ { found=1 }
   /^Filename:/              { if (found==1) { print $2; exit } }' 
$TMP_PKG`


The directories are set correctly and the  Package file exists but
tasksel-data Package in this file is not found.

Thanks.