So, I'm having trouble inserting a List, since it gives me the " Before Insert or Upsert list must not have two identically equal elements".
EDIT: SOLVED: removed code as it's 'live' code, but the jist of it is: Are you having issues when adding records to a List, and on Insert, it says you're getting dupes?
I was searching for an Account to add to a list. When I added it, I was not refreshing the "Search List" - just selecting it over and over, so literally adding the same record to the list.
I had to re-run the search after I added it to the list, so it would refresh and give me a new reference for the same Account.