We are looking at four things:
1) Are we getting slammed by spam throught the mailserver as long as the site has been around (going on eleven years), this is a very real possibility. If this is the issue, we have a solution.
2) For the early AM issues, we believe it may have to do with how we perform backups (which we do during that time). We do two backups, one a 100% tape backup and one to a storage server which only updates any changes on the server from the prevous day. It is very possible the tape backup is the issue here. If so, we'll discontinue the tape backups and invest in a different backup method.
3) Memory issue as previously mentioned, plan is in place to address this issue.
4) We are using an older version of the Forums software that is not real efficient in how it utilizes the database. Plans are in place for an upgrade, but were delayed awaiting the latest "about to be released" version of the software. Well, it has been "about to be released" for months, so we'll likely just have to do two upgrades, or get special permission to get hold of the Beta version.