Tire Bubble problems of the 2004 Jaguar X-type

I bought my car in October 2008. About a month later I noticed the tire pressure was lost frequently. I took it back to the dealer and they changed all four tires for free, stating that the tire had some rotting caused by sitting to long. Not long after I noticed the same problem and bubbles started to form on both my from tires but the dealer said it was my fault for hitting potholes and curbs. I had to purchase to additional tires on my own. The remaining two that I got from the dealer when rotated to the front, again, formed bubbles. Again I had to replace them. I spoke to a technician and explained the problem that had ben occurring. I also stated I had been more careful about my driving and had not hit the curb. He told me that there were many complains about that tire brand and they damaged very easily.