diff -rupN taxonomy_context/taxonomy_context.module taxonomy_context_new/taxonomy_context.module
--- taxonomy_context/taxonomy_context.module	2009-10-06 05:36:31.000000000 +1100
+++ taxonomy_context.module	2010-02-01 11:00:43.178052079 +1100
@@ -262,6 +262,13 @@ function taxonomy_context_nodeapi(&$node
  * Implementation of hook_init().
  */
 function taxonomy_context_init() {
+  //  THIS WAS CAUSING DEATH for anon users when caching is enabled!
+  //  Need to bootstrap so arg() is available.
+  drupal_bootstrap(DRUPAL_BOOTSTRAP_PATH);
+  if (!function_exists('arg')) {
+    return;
+  }
+
   if (arg(0) == 'taxonomy' && arg(1) == 'term' && is_numeric(arg(2)) && empty($_GET['from'])) {
     // kludge: should probably have a setting here that allows you to prevent using taxcon breadcrumbs
     drupal_set_breadcrumb(taxonomy_context_get_breadcrumb(taxonomy_context_get_context()));