I have a Bravia KDL 32EX403. The following problem has appeared on my remote control. When I try to change the channels using the numbers on the rc nothing seems to happen. I can see the green light on the tv flicking but the channels do not change. Every other button on the rc is working fine. When I access youtube on internet tv I can search and add letters with the number buttons which shows that these buttons are not broken. I can only assume I have somehow locked??? the number pad on the rc on the dtv option. Any suggestions on how to change this?

Thanks.