I have the strangest thing going on when I have motion open. While I am working a small window that has "Flip for Mac" and a status bar that says' "Importing" and when it gets to about 50% Motion dies and I get' "The application Motion quit unexpectedly." Any Ideas?
Based on reports from the Apple Motion forum, it looks like there is a problem with the free version of Flip4Mac: if you have the thumbnails enabled in the File Browser, Motion crashes when viewing the contents of a folder that contains any WMV movie files. Motion asks Quicktime to generate the thumbnail, Quicktime asks Flip4Mac to convert the WMV, and then Flip4Mac crashes. Apparently this only happens with the free version of Flip4Mac. Remember, Quicktime (and the Apple Pro Apps) doesn't natively support WMV.
The easiest workaround is to turn off the thumbnail view in the File Browser in Motion, using the list view, instead. I'd also check out the Flip4Mac site and see if they're planning to fix the problem.