Did you get to the menu at all, or it froze before it got to the menu? If it froze before it got to the menu, it could have something to do with the skin you're using. Try reformatting your microSD card using the Panasonic formatter (make a backup first), then install AKAIO 1.4.1 Proper (copy the akmenu4.nds file and __aio folder). Create a "games" folder and add a few .nds files to it. Don't do anything else. Use "safely remove hardware" before removing your microSD card, then try running it.
-Bri