I know it has happened, but I also wouldn't be terribly worried about it. The big thing is to be honest and upfront about everything with your social worker.
The cases I have heard of where people were not approved or had problems getting approved were where something in their past was not documented in their homestudy but came up after their fingerprints were run. For example, say an arrest as a teenager and they assumed the record was sealed and it wasn't worth mentioning in their homestudy. Or a situation in which they were arrested but the charges were dropped and they assumed that their record was cleared. That sort of thing.
Just be totally honest and upfront about everything with your social worker and you will be fine.
