Main page thread titles not reflected in sub forums at times

[Bigwan]

I've noticed an odd one. On the front page of the forum where the sub forums are listed with the titles of the most recent post, I've noticed (quite often recently) that there could be a title there that isn't actually present in the sub forum...

E.g. Just a second ago (11.22am to be exact) there was an N/S Stick for sale according to the front page thread title (posted at 11.04am). But in the Basses for sale forum it's nowhere to be found...