If you are watching an AVI video and suddenly the image freezes and the audio continues or pixels that distort the scene appear, it's possible that there may be a corrupt frame. There is a simple way of dealing with this: DivRepair. This tool detects the frames that are damaged and it eliminates them, so that you will be able to play the video without any problems.
DivXRepair is easy to use: you will only have to add the file that you want to repair and click on the Repair files button. DivXRepair will perform the analysis and fix the imperfections in the video. Once the process has finished it will show a report with the actions it has carried out.
Try out DivXRepair and repair the videos that you thought you had lost.