Just a quick note on disappearing threads:  If your post was clearly "below the line" (to borrow a phrase), it may have been killed by a Mod/staff member.  More than likely, however, it got killed by the community.  Members who have earned voting privileges are able to upvote or downvote threads just like they can with comments.  If a thread gets to -10 (net), it will automatically be deleted by the appropriately-named Tatum (the system that runs the site).

Dupes and low-effort posts (link and runs, etc.) will get killed on sight, just to keep the forums manageable.  Pay attention to the language included at the bottom when you click the link to create a new forum post:

Hello, and welcome to the forum. The rules here are simple:

Don't flame, be a jerk, paste premium content from other sites or otherwise make things suck.
Please try come up with a clear title that describes your post. Spell check and proof-read your post like a boss.
Give some thought to your post. Posting a single link doesn't cut it.
Pick the right forum. Don't be that person posting about Thad Matta in the Ohio State Football forum.
Did you check to make sure your post isn't a duplicate? Dupes are a quick way to earn a trip to 11W Jail.

Please review this helpful thread, along with the linked threads contained therein if you'd like more info.

And as always, keep in mind the commenting policy, which obviously applies to forum posts as well.

Cheers, and please don't kill my post!