Recent Questions Error in Questions List Macro

We get the following error message on the page when using "recent" questions in the questions list macro:

Error rendering macro 'questionslist-macro' : StatementCallback; SQL [select * from ( select "question"."CONTENTID", max("question"."CREATIONDATE"), row_number() over (order by max("question"."CREATIONDATE") desc) as "rn" from "CONTENT" "question" inner join "CONTENT_LABEL" "CONTENT_LABEL" on "CONTENT_LABEL"."CONTENTID" = "question"."CONTENTID" and "CONTENT_LABEL"."LABELID" in (-1, -1, -1, -1, -1, -1) left join "SPACES" "SPACES" on "question"."SPACEID" = "SPACES"."SPACEID" left join "SPACEPERMISSIONS" "SPACEPERMISSIONS" on "SPACES"."SPACEID" = "SPACEPERMISSIONS"."SPACEID" where "question"."PREVVER" is null and "question"."CONTENTTYPE" = 'CUSTOM' and "question"."CONTENT_STATUS" = 'current' and "question"."PLUGINKEY" = 'com.atlassian.confluence.plugins.confluence-questions:question' and ("question"."SPACEID" is null or "SPACEPERMISSIONS"."PERMTYPE" = 'VIEWSPACE' and "SPACEPERMISSIONS"."PERMGROUPNAME" is null and "SPACEPERMISSIONS"."PERMUSERNAME" is null) group by "question"."CONTENTID") a where rn > 0 and rn <= 10 order by rn]; No column name was specified for column 2 of 'a'.; nested exception is java.sql.SQLException: No column name was specified for column 2 of 'a'.

No error when the Filter by is changed to either "popular" or "unanswered."

update 23 June 2015

Similar error seen while accessing Question List Macro if filtered by 'recent' and the 'Topic' field is not empty