My job using indesign relies on the above tool on a daily basis.
I have recently upgraded to CSS from CS6 and used the DHC tool to distrubute some vertical lines at the bottom of a spread which worked fine.
However, when I select mulitple text boxes, the same option does not appear on the top of the page as I had previously with the vertical lines. To align horizonal centres of text boxes has never been an issue in the past. However, the option disappears when I direct select multple text boxes I only have the options as can be seen in the attachment.
I think what you are running into is the contextual nature of the Control panel in InDesign. You see depending on the types of objects you have selected, it shows you different options in the Control panel. Because there are so many options when dealing with text frames, there isn't enough room to show everything up there when text frames are selects. If you simply open the Align panel Window > Object & Layout > Align, you'll see that the option is available. If it's imperative that you have the distribute horizontal centers option in the Control panel, click on the Control panel menu (little guy in the way far right of your screen) and choose customize. You can then turn off some of those lesser used options so that the distribute option that you want has room to appear.