I have always checked very carefully the papers I was refereeing when I wanted to suggest "accept". Actually I spend almost as much time checking the maths of a paper I referee than checking the maths of a paper of mine (and this is very long !). But I have some doubts. Is it really my job as a referee ?

This question is related to http://mathoverflow.net/questions/36596/refereeing-a-paper but only a few comments were made on that point in the above cited thread (mainly http://mathoverflow.net/questions/36596/refereeing-a-paper/36641#36641).