The format for Insight's ~/.insightrc file changed in Insight 2.0. An
  ~/.insightrc left over from an older version might cause Insight to
  emit error messages or not work in various ways.  Just delete the old
  ~/.insightrc and restart Insight.

  Insight generates PostScript which says "language level" where it
  should say "languagelevel", and thus may not print on your printer.
  Pipe the PostScript to a file, change every "language level" in the
  file to "languagelevel" and print that.

  Insight doesn't understand the lpr printing system. To allow Insight
  to print to an lpr printer, you must provide an lp interface to it.
  See "How can I use lpr instead of or as well as lp?" in the admin FAQ.

  Insight, as well as other ViewKit applications, uses the Xpm library
  (/usr/lib/libXpm.so). If you install another version of that library
  where Insight can find it, Insight may coredump. Remove or hide the
  new version of the library.

  Greg Ferguson's <gferg@hoop.timonium.sgi.com> list of other problems
  with Insight is at
  ftp://viz.tamu.edu/pub/sgi/software/insight-problems.  Most or all
  have probably been fixed in subsequent versions of Insight and IRIX.