I'm using ImToo Video Converter Ultimate. The problem is that I can't convert a video with GPU acceleration on. However, when set to off, the video converts fine by using CPU cores. The software recognizes my graphics card but when I press the convert button (with GPU acc. on), conversion doesn't begin at all. PC SPECS: Microsoft Windows 7 Ultimate SP1 Intel Core i3 2100 AMD ATI Radeon HD 6570 1GB