Recently, when I'm in my university's library and trying to access the internet, I am unable to do so. Even if my wireless bars are all black and darkened, my internet doesn't seem to load, or it takes a long time to do so. Sometimes, I need to exit out of Safari and turn airport on/off a few times to get the internet access back on. Sometimes that doesn't work, and I just have to wait a while. Is this "normal"? Does this suggest something is wrong with my macbook pro's wireless card?