Have you used the following route to contact Adobe about your issues and concerns?
If your Premiere Elements 11 Windows falls under the category of purchased/registered/current version, you might want to explore the possibility of free Adobe Technical Service direct from Adobe.
The answers are based on details so for either route be prepared to give details that you have not presented here...computer environment, length of the uncompressed avi, et al. Most of these capture programs require conversion to another format before importing into Premiere Elements. Typically the manufacturer of the capture software writes that into their instructions. And Virtual Dub is a common recommendation by such a manufacturer. By the way, a just in case note, .avi is just a wrapper format that wrapping the video and audio compression. And, an .avi file can have several different video/audio compression. So, there are many types of an .avi file. What type of .avi did you export from Virtual Dub...what was the video and audio compression + the .avi wrapper that worked for you to get the "uncompressed avi" converted to ".avi" and then into intact Premiere Elements 11?
>raw, uncompressed AVI format
AVI is a "wrapper" that may contain any number of video files... not all of which edit well
Read Bill Hunt on a file type as WRAPPER http://forums.adobe.com/thread/440037
What is a CODEC... a Primer http://forums.adobe.com/thread/546811
What CODEC is INSIDE that file? http://forums.adobe.com/thread/440037
Report back with the codec details of your file, use the programs below... A screen shot works well to SHOW people what you are doing