Why does my Class 10 memory card run in to buffering problems?
You don't mention which Transcend card you bought but the benchmarks here indicate that the write throughput performance of Transcend cards are a little under 10 Mbps (naively I assume this is true for their brand of SD cards but I could be wrong). Strictly speaking the SD Card class rating seems to imply 10 Mbps minimum for 1080p recording so that may partially explain why you are seeing that behavior with your camera. 

If you can try other manufacturers, look at their benchmarks from them as well as reviews to see how it goes.