Multiple posts temp tables created cause a massive load on the server and inevitably a shut down.

D6

I've been having an issue that is driving me crazy.

There is a mass amount of temp tables that are being created.
The issue is that the temp tables created cause a massive load on the server, and when multiple posts are done at the same time the load skyrockets until the server crashes.
See the processlist below:

| ###### | NAME | NAME | NAME | Query   | 35   | Copying to tmp table | SELECT DISTINCT(node.nid) AS nid,
   flashvideo.nid AS flashvideo_nid,
   node.title AS node_title,

I've tried a lot of things, yet none fix these specific processes.

Any help pointing me in the right direction would be most appreciated.

- Jesse