Just got a Hatachi TV, whenever i try to change channel on my Cable remote, The TV switches channel, WHY? Help

Just purchased an Hitachi 37" LCD TV from Argos and have connected it up using HDMI and Scart to my Virgin V+ cable box. Now whenever i switch the tv to the AV source (Being Cable) and then try channel hopping on the Cable remote, the TV channel reverts back to DTV or TV and changes to channel 7, 77 or 777 depending on how many times i press a on. (Though the cable channels do change, but i cant see this as the tv has change the picture!) IT seems the infared sensors pick up everything I press on the cable remote, if i hide the cable remote from the TV, the cable box works fine, this is so wierd and wondered if anyone new a way to STOP the TV from picking up the sensor from the cable remote???