# apt-get update
[... hits ...]
Reading Package Lists... Error!
E: Encountered a section with no Package: header
E: Problem with MergeList /var/lib/apt/lists/_var_cache_apt-build_repository_dists_apt-build_main_binary-i386_Packages
E: The package lists or status file could not be parsed or opened.
update available list script returned error exit status 1. Press <enter> to continue.
Then I did this:
# mv /var/lib/apt/lists/_var_cache_apt-build_repository_dists_apt-build_main_binary-i386_Packages /var/lib/apt/lists/_var_cache_apt-build_repository_dists_apt-build_main_binary-i386_Packages-old
# dselect
... and now everything is back to normal. Still, it doesn't explain why it did not work before, but I hope this helps.
Anthony

