Resolved inline comments cannot be deleted. You have to reopen (unresolve) the comment and then delete. There should be a "Delete" link in the Resolved Comments window so you can delete without having to reopen first.

To reproduce:

• add an inline comment to a page
• resolve the comment
• view the resolved comment via the page more actions menu - there is no way to delete it but there should be
• reopen the resolved comment
• now you can delete it via the inline comment more actions menu