So IG spawners are kinda pig spawners when placed down. I for one think that's a problem. Below are the results of a test for this (reimbursement for the spawner would be nice if possible).
Thank you for this, but we already know and are working on it. For the time being, please spread the word of not to break or place any spawners and once this is fixed we will change the pig spawner back into Iron Golem for you. Sorry for the inconvenience