After installing PE7 (it replaced PE3), I set about seeing what PE3 projects it could open. Turns out it could open most of them. But a couple caused it to crash while opening. These projects (if I remember correctly) had a lot of h.264 clips in them, although PE3 could open them. As PE7 tried to open them, it also opened a new instance of ffdshow (ie., an icon in the driver tray) for some, if not all, h.264 clips in the project. One project must have had at least 10 ffdshow icons in the tray before it crashed PE7. Other projects that also have h.264 clips in them did not cause PE7 to open instances of ffdshow. And PE3 NEVER opened instances of ffdshow.
I simply deleted the projects that caused PE7 to crash while opening because I have AVIs of them that I rendered with PE3. But I have a couple projects that open one or two instances of ffdshow but do not crash. I'm wondering what is different about the projects that cause it to open fdshow and those that don't. Anyone have any idea? Why would PE7 open some h.264 clips without ffdshow and some with it? The clips are all made with the same camera and aside from length and content should look the same to PE7.
In my next experiemnt, I am going to disable ffdshow and see what happens when I open a project that also opens a couple instances of ffdshow.... PE7 should be able to handle h.264 clips without ffdshow, right? And then I may delete all the aux files for that project (generated originally by PE3) and force PE7 to re-make the ones it needs.