Remote

On many occasions I can switch to a channel on my remote but I get a little sound and a blank screen then a soundless blank screen for that channel.  I can try going back to the "last" channel and back again but I get no picture or sound.  The only way I can get the channel back is to switch down or up to the next channel then immediately back to the channel I am not receiving.  This usually restores sound and picture but doesn`t allow me to go back to the last channel using that feature on the remote.  I have to do that by selecting the numbers for the channel.  Is there a problem with my remote or is it the cable box dropping the remote signal?