The board search engine has been a little tetchy as of late. Please have patience, as there are many little quirks being worked on to get the new board up and running as it should. One point, though. I don't think you will get very good results from searching only for the word "or." It is just too common a word.
If you are looking for your own posts, however, you can click the Profile button under any of your posts, then click the text link for "Find all posts by em." It will be in the top orange border on the right side.
You can also search by username in the search engine (you'll essentially get the same results).
Hope it helps,