Besides the elements Bolimomo said above, reducing the recording frame rate can also reduce the file size of the screencast. To improve your computer¡¯s performance during the screen-capture session, especially if you plan to capture the entire computer screen, reduce the screen resolution and color quality. If you plan to capture full-motion video during your screen-capture session, disable your computer's hardware acceleration. That will make your computer runs more smoothly when in recording. More tips for making good screen recording: http://www.sameshow.com/democreator/article/screencasting-tips.html
Been using Camtasia to record my trading desktop and my live voice narration through the headset. Unfortunately, the video and audio go out of sync within a matter of minutes, progressively getting worse and worse. I'm recording one 1920x1200 screen, tried all sorts of combos of video and audio encoding, disabling hw acceleration, recording a smaller screen size, but the video and audio always end up out of sync. This is on a new i7 Quad Core with 12GB RAM running XP Pro 64. Anyone else experience this/have found a solution?