There was an issue with physical screen size detection some time ago, in a version of X. This caused extremely small, or large fonts to be displayed instead of normal sized fonts.

The problem is effected within the development versions of X within Debian lenny/sid, perhaps on other distributions as well.

However, there is a work around using the xrandr command (which is used to set size, orientation and/or reflection of the outputs for a screen*). The work around is as follows.

Append to /etc/X11/Xsession,

/usr/bin/xrandr –fbmm XxY

Were X and Y are your real physical screen sizes (get a ruler!) in mm.

My laptop runs on, 330×270, so I therefore have:

/usr/bin/xrandr –fbmm 330×270

As my last entry within this file.

Note, this seems to have been fixed in recent versions of X, so this doesn’t exactly apply to up-to-date systems any more.

I am also not sure whether the small font issue is the same as the large font issue, but it makes sense that it would be. This work around should work for small font issue as well.

* Taken from `man xrandr`