>Have you tried with a different font (e.g. Lucida Console -- assuming you have monospace fonts other than the standard bitmapped ones)? One thing to note however sometimes the box draw characters (as well as some of the other characters in the 128-255 range) may not display as expected because the font is based on a different codepage than the one used in DOS (typically 437 or 850). The other thing that might not match is the aspect ratio -- typically the screen will end up looking too narrow for the width, or too wide for the height.

Have you ever experimented with DEVICE=Drive\Path\ANSI.SYS in CONFIG.NT? I'm wondering if it would make any difference, in this case.