After upgrading from a single-core to a dual-core CPU (AMD Athlon 64 X2 4800+) and a new mainboard I got a very annoying problem with Civilization 4 under Windows XP. All the ingame videos (intros, wonder movies etc.) started to stutter and eventually froze after a few seconds. The sound startet looping faster and faster until freezing too. Sometimes the freeze stopped after a while and the stuttering and looping began again. Sometimes I even had to reset my computer to get out of a very prolonged freeze. My first solution was to disable the movies entirely or to click fast enough to skip the movie before it gets the chance to freeze. After trying a lot of things with CPU, nvidia video and mainboard drivers and binkw32.dll files, I came finally up with a better solution: 1. Install the "AMD Dual-Core Optimizer" 2. Set "SyncInput" in your CivilizationIV.ini from "0" to "1". 3. Enjoy smooth playing ingame-videos. I don't know, if the first step is really necessary, but to install the AMD Dual-Core Optimizer under XP is recommended anyway. I hope I could help at least someone with this.