--- fieldgroup.module.orig      2009-01-10 16:47:07.000000000 -0600
+++ fieldgroup.module   2009-02-13 16:34:14.000000000 -0600
@@ -91,7 +91,7 @@
 function fieldgroup_content_fieldapi($op, $field) {
   switch ($op) {
     case 'delete instance':
-      db_query("DELETE FROM {". fieldgroup_fields_tablename() ."} WHERE field_name = '%s'", $field['field_name']);
+      db_query("DELETE FROM {". fieldgroup_fields_tablename() ."} WHERE field_name = '%s' and type_name = '%s'", $field['field_name'], $field['type_name']);
       cache_clear_all('fieldgroup_data', content_cache_tablename());
       break;
   }