I have a D-Link AirPlus wireless card and when I installed it the first time and plugged it in it worked... until I turned the computer off. After that, I reinstalled it and it worked again but whenever I take the card out, put my laptop to sleep, or turn it off, I have to reinstall the wireless card in order to get a connection. I don't think that this is how the device is supposed to be functioning. D: D:

OK when you remove the card is the machine still running as this may be causing your issue.
ONLY add/remove the card when the machine if OFF.