Greetings: The problem: When I build Kdenlive for my Arch 64 system it compiles without problems and starts up okay. After that the sluggishness of its response is almost unbearable. For example, I've timed up to 10 seconds between a mouse click and the resulting action, e.g. right-click to Add Clip, and everything stalls badly when the program is calculating audio or video thumbnails. Response time gets better after running the program for a while, but getting it going is rather frustrating. I've already searched Google and asked about the problem on the Kdenlive forum and got no useful replies, hence my request here. Some of you use Arch systems, and some of you know Qt well enough that maybe you can advise me on this problem. (I'm hoping for a relatively simple solution, of course). Incidentally, the problem occurs with Arch's packaged Kdenlive and the binary I compile with the build script. I just upgraded both, the problem is still there. Other large Qt apps don't have the problem, e.g. QTractor. The problem is also absent with Kdenlive on my 32-bit machines. Btw, video is an nVidia GeForce 7600 GS, with nVidia's driver. Best, dp