i know a lot of people use camtasia to make many of the video tutorials you see here. i’m sure they have a free trial if you wanted to check that out…
as far as the footage issue, the avi container is usually not a problem… do you know what codec snagit is encoding the screen captures as, and can you set it to use a different codec?
usually the first step in troubleshooting footage problems is knowing as much about the footage as you can. knowing the codec can go a long way to fixing footage issues. if it is recording using a codec like mpeg-2, mpeg-4 or h.264, then it is probably using interframe compression. this type of compression will create problems for ae. you should be able to convert it using an nle or another media utility to codec that uses only intraframe compression or no compression.
other potential issues with footage could be how ae interprets the footage. select the footage in the project window, choose file>interpret footage>main. since it is a screen capture, make sure that ae is not separating fields. also make sure that the frame rate is correct.
Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW