[edited after receiving the solution from caker and mikegrb in irc]

Upgrading from woody 3.0r1->sarge was trouble-free a couple weeks ago but now, the screen freezes.

During apt-get dist-upgrade, some dialog prompts are freezing in mid-display. For example, the dialog about keymaps (the one diplaying all the countries) hangs. I've noticed that the dialog borders are funky-looking characters so that might indicate the source of the problem.

SOLUTION:

caker helped me figure out the problem only occurs when using Lish. Going directly to the Linode via ssh works fine.

mikegrb suggested the following solution which works great when using dialogs in Lish (thanks mikegrb!):

export TERM=screen

Before this, I was using a workaround suggested by #debian folks to use another terminal to issue a 'kill -STOP and kill-CONT'. That unfreezes it but requires another terminal.

While troubleshooting this I got some advice about locales from various channels. Seems en_US should be prefered over en_US.utf8 unless there is a good reason (the issues they encountered with en_US.utf8 might no longer be valid in more recent distros & apps).

SUGGESTION
Since issues (user errors or bugs) like this can cause a upgrade to take longer than expected, I'm wondering if we can have a more up-to-date & secure debian distro as a starting point (like woody 3.0r4).

UML security claims (as of March 2004) like the following (which I hope is no longer valid) make it important to provide default distros with security holes already patched:

http://uml.harlowhill.com/index.php/Security