Make sure you using the correct case as it is case sensitive. My problem was resolved when i used lower case.
We have just bought a 40" 8000 series Samsung led TV (brilliant!) and the Samsung wireless dongle. I have followed all the instructions in the TV manual and our home network is seen, properly named and full signal strength shown. But when I enter our security code I keep getting a 'connection failed' message. Our 2 laptops connect perfectly well to this network using the same security key but the TV won't - am I mising something? Any help much appreciated.