It sounds you forgot to try out the betas I suggested. Sometimes jum's versions work where the official version doesn't.

Perhaps it is a G3 issue I don't know. I presume you have slower ram, slower bus speed, etc. If the issue isn't Java or Prefs which are generally the 2 things that do repair that type of issue for both mac & windows, then I guess either a reinstall of LW or a system issue. I guess the alternative is to use an older version like one of the earlier 4.9 versions or 4.8.1

Which version of LW were you using before you updated?