WCAG 1.0 Checkpoint 3.4

dear members,

since i'm not entirely sure where to place this question, please accept
my apologies if this is not the correct location.

this is a request for clarification on point 3.4 of the web content
accessibility guide:

http://www.w3.org/TR/WCAG10/ states "3.4 Use relative rather than
absolute units in markup language attribute values and style sheet
property values.".

http://www.w3.org/WAI/GL/WAI-WEBCONTENT-ERRATA states "...If absolute
units are used, validate that the rendered content is usable...".

as point 3.4 seems to be primarily aiming font size or table cells,
would it make sense to use the "@media screen" directive to limit the
width of the content area of HTML pages to 600 pixels for layout (and
print) purposes? while doing so it is assumed that 1) there are no
screens with resolutions of less than 640 x 480, 2) the CSS[2]
directives can be overridden by most agents, and 3) it is more difficult
to follow content that spans over the whole screen width.

regards,
  shady