No prob. Try clicking on whichever of the markers you'd like to delete. Don't use the find feature for this... actually click on the little pin which corresponds to the site you're trying to get rid of. A bubble should pop up with your name, and two options.... "Edit this site" and "Delete this site". Click the delete link.

Let me know if it doesn't work, tell me which you want removed and I'll go in through the database side and do it.