Monetdb crashed as group by

select sum(minutosfacturados),succodigo,montht,comnombre2 from bi_con_cdr_diario as cdr inner join timedimension as td on cdr.idtimedimension=td.id where comcodigo=4 group by succodigo,comnombre2,montht; but for example as this query work fine: select sum(minutosfacturados),succodigo,montht from bi_con_cdr_diario as cdr inner join timedimension as td on cdr.idtimedimension=td.id where comcodigo=4 group by succodigo,montht; What i need to do for to fix this? Thanks Edgar M