FYI, it just happened again. Since this post has miraculously survived on the forum for 16 hours, I thought that perhaps I could re-post my original post.
No such luck. The difference this time is that while the original post actually appeared on the site for at least a few seconds, this time, the post disappeared as soon as I hit the 'Post' button, and I was taken to a page which said something like 'Topic Not Found'.
I expect it will be extremely difficult for me to use the Yahoo! API effectively if I can't discuss it with more experienced developers. If I am somehow violating some kind of guidelines with the content of my disappearing posts (which I suspect is what's happening), then I would appreciate it if Yahoo! would explain exactly what I'm doing wrong.
I recently had a post 'disappear' overnight as well. Around the same time a vaguely similar question appeared by a new user. This could have easily been a coincidence since I imagine it is a very common problem, but I have the same worries about whether or not I'm breaking some unstated rule.
More clarity about why posts are removed (content, rules, flaky forum system, etc.) would be greatly appreciated.
What is happening is that we have a large list of blocked words/phrases because of spam detection and some forum posts may trigger that system. We are typically able to free them quickly, but a bug has occurred that is causing the spam queue not to render.
We are working on a fix but it may not be fixed for several weeks. I'm really sorry this is affecting your posting to the forum.