I don't know what happened to my 23+ minute video but the very next day when trying to open the 2111mb file it came up as being broken. I thought this meant that the links to the media was broken, but that turned out wrong. I tried everything I could think of to retrieve the edits in this file or fix what was wrong with it, following various directions found on the web and in forums. Like locate the *.pds.bak file and remove the .bak suffix (no such thing on my computer), or open a good *.pds file, copy the last four lines while open in Notepad and replace the last four lines in the broken file with them (NADA), and then there was a reference to a patch file put out by CyberLink to fix this very problem (couldn't find it anywhere). Finally I checked my Preferences>Project>Save location, went there and found my AutoSave file. No wonder my searching couldn't locate anything similiar to it, the whole address was strung into the name there. Copied that file back into my working directory, so it could access the files in there and double clicked on it. I had to go back a few autosave files before one would work but finally it did. I then changed the name of the pds file and am now incrementing the file name with each save.
The day before I had a RoboHelp CHM file I built and maintain corrupt a single internal htm file, messing with its masterpage. Turns out RoboHelp 9 doesn't work well with multi embedded tables and I had to remove all of those before I could fix the problem. I finally fixed it and then ran into this video problem. Made me think that maybe I had a virus or something so I did a 3 hour check and McAfee came up empty so I can't really say the two are related now.