Items in the "Post List" are from the "Topics" table (as the posts table doesn't even have an "is approved" column). It is not recommended to go in and remove items directly from the database as it can lead to more issues (that won't be supported under the standard level of official support; keep in mind that these forums are for user to user support).
A date of 1969 says that the timestamp of the entry in the topics table is 0 (as you can't figure out the amount of seconds since the Unix Epoch if it is 0, as 0 would be before 1970).
The Thread ID shown when you hover over the link is what you'd want to search for in the TopicID or PostID field of the _TOPICS table (or you could just see what's not approved by sorting by the "TOPIC_IS_APPROVED" column).
