Mail not displaying folders right!

Hey all,

Just got my new MacBook! Yay!

But when I use Mail, I have two accounts setup and the folders on the left display fine for one, i.e. they are under a drop down with the account name. But for my other account, the folders are under the top drop down, instead of under the drop down with the account name. So a bit like this:

> Folders
.....> Account 1
............Folder 1
............Folder 2
............Folder 3
..... Account 2
Folder 1
Folder 2
Folder 3

Why arn't the folders showing under Account 2?! Both accounts are IMAP and setup in exactly the same way!

I havn't updated using software update yet, but I will do that tonight - could that fix it?