I went through my (un)deletion votes on my profile page today and discovered that at least 5 are missing.
In the deletion tab, only 5 votes appear:
That can't be true. I don't recall every deletion vote I cast, but I know that I ran out of deletion votes once, so there are at least 4 votes missing.
Likewise, the undelete tab shows only 5 votes:
I cast all those votes on my own answers. However, I voted to undelete the question How to destroy all hard drives contents as fast as possible?. That vote is missing.