Channels 951 to 1959 disappeared from guide. What happened?

select "hd only".

Cox converted all SD channels in Tulsa with an HD equivalent to HD over two years ago.  The channels from 1000-1950 were duplicates of the lower channels. 

Trying to select only a lower channel or a 1000+ channel as a favorite was always a frustrating exercise.  Adding a channel as a favorite also added the equivalent channel.  Removing the equivalent channel favorite then removed the selected channel.  Eventually, only desired channels could be selected, at least temporarily, but not until after pegging your frustration meter.  Removing the upper channel duplicates will make setting up favorites much easier.

Recordings selected for a lower channel also appeared in the program guide as selected recordings for the 1000+ equivalent channel, and vice-versa.  However, only the channel actually selected was recorded. The duplicate scheduled recording indicated in the program guide had to be ignored when trying to resolve recording conflicts. 

Selecting the duplicate channel when attempting to cancel a selected recording produced a non-descriptive error.  A  recording could only be canceled by selecting the channel originally selected to be recorded.  Once this was known, it was easily managed by only selecting programs to record from lower channels or only from higher channels.  But, it was another frustration until it was understood why the error occurred while attempting to delete a scheduled recording from the program guide.

Channels 951-999 were Cox channels, still available from 1960-1998 for anyone who cares.