Now, it could be that these abilities are considered to be the same thing, which is a GM call. Personally, they have designed the Jedi classes rather poorly in that standard classes and prestige classes have matching abilities, which is rather silly to me. A bunch of Jedi prestige classes give those Deflect (defense) and Deflect (attack) abilities, when you would almost certainly already have those from your base class. Not sure why the designers felt they had to give those abilities again unless they either 1) didn't realize you already get them or, 2) intend them to stack.
For example, two of the Jedi prestige classes from the Revised rules, the Jedi Investigator and the Jedi Master, both give you Deflect (Defense) +1. In order to get into these classes, you have to have several levels of either Jedi Consular or Jedi Guardian, both of which give the same ability at 1st level. If they are not intended to stack, these are pointless class abilities.