NVIDIA yesterday announced that profits in its fourth-quarter surged to US$73 million, more than twice what it posted in the year-ago quarter. Revenues also more than doubled to $499.9 million, largely attributed to Microsoft’s NVIDIA-powered Xbox video game console. The company also informed investors that its accounting practices are currently being investigated by the Securities and Exchange Commission. While analysts don’t expect any repercussions from the probe, shares of NVIDIA fell nearly 10 percent in after-hours trading.