a SRAM X.O ten speed rear derailleur on a road bike with an 11X34 cassette and dura ace 10 speed shifter. The combination does not seem to be working. I have a road rider who does a lot of mountain road climbs. We can get about 7 low gears or 7 high gears but cannot get full range.

The SRAM X.X series shifters and derailers use a different cable pull ratio to Shimano parts. You must match X series shifters with X series derailers.

You can buy a travel adjust which alters the cable pull. Can't remember which direction it works in though.

The SRAM X.0 derailleur is a 9 speed device not 10. It will work with the 11/34 cassette which is also a 9 speed device. The Shimano Dura-Ace 10 speed shifter is not a 9 speed device and has the wrong cable pull for either the X.0 derailleur as mentioned above, or the 11/34 cassette if used with a correct derailleur.

Yea, anything SRAM that say "1:1" or "Blackbox" or "Zero" or "Zero Loss Travel" will be SRAM only.

or ESP

Actually, BlackBox is just the name for the carbon derailleur cage.

Black Box is the name of SRAM's racing development program. Some of the parts developed in that program bear the label "Black Box" due to marketing.

I have only seen Blackbox or the CF cage on 1:1 stuff.