how to clock an upcoming show to automatically change to that channel at the right time

Just got the Contour box as my old motorola gave out.  I used to be able to find an upcoming show and clock it so the tuner would automatically change to that channel at the time the show was on.  Now I can set a "reminder" but it won't actually change the channel for me.  Not very handy when you aren't sitting right in front of the tv when the reminder comes on.

Is there a way to make it do this?????  I liked my old motorola box....