I had tried installing the Zoints SEO, but it didn't work with the mod_rewrite well so I had to revert the things.
I am doing what you said.
EDIT
It's fixed now. It was the Zoint's SEO forumhome_lastpostby template which was messed up. Replaced it with the default one

.
Thanks for the awesome help(s), Lynne. You're always help us and really make vBulletin.org's forum a better place

.