I noticed something really strange with google serps for some of my pages; when searching for the exact title of the page (tried in quotes and not in quotes), it doesn't come up in results, but sites that have copied my content do. Furthermore the url from my RSS feed sometimes appears instead (which redirects to the page in question)
If I do a good old site:url.com the page is in the index.
If it makes a difference the site is a large forum that is 10+ years old.
What's going on here?