Finder windows having to load for file attachments?

So when I try to attach a document to an e-mail I noticed Finder is taking a long while to load the contents of my folders. In Mountain Lion and prior this was instant but now I get a loading circle that takes about ten seconds before I can move through my file system.

Any idea what is going on? I'm running a topped out rMBP 15" so the computer's ability to process this task should not be an issue. I don't think It'd be an issue for my 1997 Compaq either.