I plan on getting Chessmaster or Fritz sometime soon. I agree that this program wasn't very good. The point of 1...a5 is to let White build a classical center which can then be attacked. Bringing the rook out early is an option; so is a fianchettoed bishop.
I have to wonder if 1...h6 might work better, like a reversed St. George defense.
<duskwalker> The strength of your computer opponent does not help your case; it plays no better than a 1400 player (which may be too generous.) You also failed to show the importance of the moves "a5" and "Ra6" which merely led to a rook exchange at the cost of time. Try the opening out against someone (not a computer) of at least 1600 strength, and you don't even have to win-just show that it does something worthwhile, which most everybody agrees, it doesn't.
Also, 16. Bxb5 leads to 16...Nxe5 17. Nxe5 (Bxd7 Nxd7) Bxb5 which loses a central pawn for a doubled pawn. Why did you play b5 if you did not know the Nxe5 trick?