alcaucin:More likely your ball had run out of life...you only get so many hits per ball
Yep, and to take it a step further, the little meter to the right of the ball that says "hits" shows you the approximate ball life left - red indicating it is nearly used up.
For the record, I would use cheaper balls at your level and with your clubs. For a start you will tend to lose more balls as a new player and secondly you will not get the full benefits the ball offer with your clubs. Personally I would use one of the cheaper WGT balls that offer a bit more spin and distance.