This happens sometimes. You write a post, try to post it, get an error but it shows up on the front page anyways. Then you check on the thread itself and it's not there. Sometimes it shows up in the thread eventually, after 10 to 15 minutes or so, sometimes it never shows up.

I wrote a post about flowers there, got an error, it shows in the home page but not on the intended thread. A few posts bellow, the one that starts with '>>40107 Lain and uboa comes up with interesting stuff every...' is also showing up at home but not on the thread intended.