Are you using the dash (-) between the freeview channel numbers? I know in the U.S., sometimes that can make a difference. If it happens when you hit the first number, then I would definitely recommend calling the Samsung customer service center in your region to see if they can troubleshoot further.
l have just bought a LE32B450C, everything works fine all my freeview
are loaded , but when you press the numbers l get weak signal notice, but when l press the up and down buttons ,it works perfectly,we have just gone off ann to digital,any help plese