Clicking on the statistics for the survey produces a error 500 .
CDbCommand failed to execute the SQL statement: SQLSTATE[42601]: Syntax error: 7 ERROR: syntax error at or near "group"

Looking in the postgresql database log I can see that there is a quotes problem in the order by:
SELECT
"t"."qid" AS "t0_c0",
"t"."parent_qid" AS "t0_c1",
"t"."sid" AS "t0_c2",
"t"."gid" AS "t0_c3",
"t"."type" AS "t0_c4",
"t"."title" AS "t0_c5",
"t"."preg" AS "t0_c6",
"t"."other" AS "t0_c7",
"t"."mandatory" AS "t0_c8",
"t"."question_order" AS "t0_c9",
"t"."scale_id" AS "t0_c10",
"t"."same_default" AS "t0_c11",
"t"."relevance" AS "t0_c12",
"t"."modulename" AS "t0_c13",
"t"."encrypted" AS "t0_c14",
"t"."question_theme_name" AS "t0_c15",
"group"."gid" AS "t1_c0",
"group"."sid" AS "t1_c1",
"group"."group_order" AS "t1_c2",
"group"."randomization_group" AS "t1_c3",
"group"."grelevance" AS "t1_c4"
FROM "lime_questions" "t"
LEFT OUTER JOIN "lime_groups" "group" ON ("t"."gid"="group"."gid")
WHERE ((parent_qid = 0) AND (t.sid=499767)) ORDER BY group.group_order,question_order

For this query to run it should be using quotes:
ORDER BY "group"."group_order",question_order