Good spotting there, Frostwake. I haven't noticed that myself.

Apparantly the FFII, III and IV forums are set to show all threads, while the rest of the FF forums are set to show only threads that's been active the last month. So there you have it, the missing threads in the FFI forum is not gone, just not displayed. Go check out the options at the bottom of the page if you want to view threads that are older than a month.

I have no idea why the forums have different settings though.