This post has somehow been parented to itself. The "Parent" field is empty when I try to edit it, though.

post #1363598 (which is deleted) was child'ed to this post; removing this from its parent field stopped the apparent "self parenting"

Gollgagh said:
post #1363598 (which is deleted) was child'ed to this post; removing this from its parent field stopped the apparent "self parenting"

Ah, that would explain it.