dia shows ugly bitmap font

[Zhang Weiwu <zhangweiwu realss com>]

Hello. Thanks to the ultra complicated graph I often work with, even
though my display is more detail than XGA display mode, I still need the
normal texts in the graphs to be the smallest identifiable size to
contain enough graphics in the viewport. The only way I can think of is
to use bitmap font. e.g. Fixed:style=Regular can display identifiable
font at 7 pixel size.

However I have two problems:

   1. When I configure dia to use Fixed as normal text font for a graph,
      it become junk character. You can find the difference between
      using Fixed and "Droid Sans Mono" as normal text font at the same
      font size, by looking at the attached screenshot (be warned, it is
      very big, 2KB in size;)
   2. The font size measurement unit is rather strange to me. By default
      it has 0.80 for normal text. 0.8 does not look like any font
      measurement unit I knew of (px, pt, inch), thus I don't know how
      to specify this value to get the 7px font size I want to have.

I just wonder if other people already have a solution or had the same
problem?