After you added the hidden menu to make it display in another page, I'm getting one column no matter what I've done so far. I turned off your hidden menu option that didn't make a difference.
#2 If I add the date to "Show" in Chrome it's fine, in FF it overlaps the blog title, (no picture) we won't even go into Safari, I have the OLD latest version and nothing is right layout wise but, I'm not a Apple lover so don't care. )