Just curious. My shader had some of these variables and I wasn't able to read their values and when adding them to a watch list they had an invalid expression for a value. Giving them a longer name worked. But why?

Which version of Visual Studio were you using, and on which operating system? Also, was there a particular type of variable that had the issue (i.e. local, a certain type, input/output registers, etc...)? If you post a shader, we could try it out to see if it occurs the same on our end.