Korn's Groovy Pirate Ghost Mystery - S3-E10
Corrected entry: When the boys dig up Kyle's dead grandmother, the last name on the tombstone is "Broflovski." But when the cemetery people go to Kyle's house to tell his parents what happened, they tell his mother "your mother" has been dug up. Unless her maiden name is also "Broflovski," which is unlikely, the dead woman would have to be Kyle's father's mother.
Korn's Groovy Pirate Ghost Mystery - S3-E10
Corrected entry: Why doesn't Kyle's Grandma's grave have a Star of David on it? The Brofloskis are Jewish.
Correction: Kyle's grandmother would not be a Broslofski by birth - her family may not have been Jewish.
Correction: While rare, it's not completely uncommon for a man to adopt the wife's maiden name after marriage. Given Sheila's commanding personality compared to Gerald, it's possible she got him to change his name to Broflovski when they were married.