Do you have a pesky memory in your memories that leads nowhere because the original poster has deleted the original post? Do this to make it go away:

Go to your memories page. Click on the category that contains the entry you want to delete. You should get a list of posts under that category. The page will say "Memorable [category] Posts."

Add the following: &multidelete=1 to the end of the URL of that page and hit enter. It will give you a box beside each post that will allow you to delete whichever you choose.