The problem happens with any kind of project, like 720x576 or 1920x1080, and very often the case if the timeline I have the.mov, sometimes with.mxf. Usually we don't even have 'real' montages, only clean the clips, so we don't place any effect or special things, we only cut clip and join. I also tried to put stress on the PC with appropriate programs, but didn't give me big problems. Another thing I noticed exporting a project is that disabling the GPU pc memory is filled to about 30gb and then freeze the computer, while activating GPU uses only 10gb but after a while still freeze.