Should always selecting the same response on the IOWA Gambling Test result in a good value? I was taking the Iowa Gambling Task. 
I examined what happens when the same option is selected on every run.
To my surprise I got a pretty good value when choosing options C and D (\$4500) in every run and a pretty bad one ($-500) with options A and B.

Is this intended by the test or is it a bug / feature of my downloaded program?

(I got $4700 when mixing some A's among plenty of C's)
In the standard version of the task there are "good" decks (overall positive payoff) and "bad" decks (overall negative payoff), so the optimal strategy is to figure out which ones are the good decks and stick with those. In principle, which deck is which should be randomized, but I don't know if your version implements that. There are also many variations that manipulate amount of gain/loss (e.g., rare big gains vs. consistent small gains) or change the payoffs in the middle, so the optimal strategy can vary.