Fixed ISO images for Debian 6.0.1 has been released. Here the announcement:

Post-release testing showed up a variety of bugs in the images produced
for the 6.0.1 update release [1]:

1. Wrong installer code used for the "small" CDs

The script used to build the netinst and businesscard CDs was
misconfigured, and was using the testing (Wheezy) version of
Debian Installer instead of the correct Squeeze version.

2. Incorrectly sized DVD images for some architectures

During the original 6.0.0 Squeeze release, we encountered problems
in making some of the CD images fit; once the Squeeze release notes
were added, the alternate KDE installation CD for several of the
architectures grew too large. A number of last-minute tweaks were
made on that release day to try to fix this, and the problem was
mitigated. Unfortunately, (as is often the case with quick hacks in
these situations) these tweaks did not work well in the next
release and caused unforeseen problems. Various of the 6.0.1 images
that should have been sized to fill a DVD were instead limited to
approximately 700 MiB.

3. Update CDs and DVDs missing Packages and Sources files

In between the Lenny and Squeeze releases, a fair amount of the
code in the debian-cd package was refactored for clarity and to
aid in maintenance. This also included deleting some older helper
scripts that seemed to be redundant. Unfortunately, that conclusion
was incorrect; two scripts were removed that were necessary for the
correct operation of the "update-cd" script that generates the
update CD and DVD images. Due to this oversight, on the day of the
point release those images were created wrongly. They contained
package and source data, but the meta data files Packages.gz and
Sources.gz were missing.


In each of the cases listed above, the failure case has been analysed
and is understood. Fixes for all of the problems have been developed,
and replacement images have been produced and tested. Following our
normal naming scheme, the new images are versioned 6.0.1a to denote the
bugfix rebuild.

There is no need to download these new images for user who have already
downloaded previous images versioned as 6.0.1, if they are not affected
by one of the bugs listed above. The easiest way to create fixed
images for users who are affected by these bugs, is to use jigdo and
scan the previous images for already downloaded files.

We offer apologies for any inconvenience caused by these errors. The
very next task for the Debian CD team will be to integrate more
extensive automated QA for our CD images, in the hope that we will
significantly reduce the likelihood of bugs like these in the future.

1: http://www.debian.org/News/2011/20110319
2: http://www.debian.org/CD/jigdo-cd/#how


About Debian
------------

The Debian Project was founded in 1993 by Ian Murdock to be a truly free
community project. Since then the project has grown to be one of the
largest and most influential open source projects. Over three thousand
volunteers from all over the world work together to create and maintain
Debian software. Translated into over 70 languages, and supporting a
huge range of computer types, Debian calls itself the "universal
operating system".