LR 5.2 on Mac Pro running OS 10.8.5. (2.66 GHz Quad-Core, 24 GB RAM). LR Catalog is located in Pictures folder on main HD, image files are on internal HD titled Working Drive.
I import direct from CF card to LR in Library module (in other words, I don't import card to desktop then import from HD).
As far as I know, my settings and methodology has not changed since the upgrade from LR3.
When I Import, I create a new job folder on my Working Studio HD, which is setup in a series of "bucket" subfolders similar to Peter Kroghs DAM system. After hitting the "create" button in the appropriate folder from within LR, I'm back in LR, but the newly created folder does not show in the import pane and even after finding a workaround and importing files, shutting down LR and restarting, sometimes the folder I created doesn't even show up in thge Library/Folder pane (left side).
One additional piece of information. I upgraded from Snow Leopard to Mountain Lion at the same time I upgraded from LR3 to 5 and I am getting a lot of spinning beach balls between programs and when navigating folders. I have switched Spotlight off for my Working Studio HD, but I do wonder if there's an issue between LR and the OS.