I always have "use external binary morphs" unchecked. It's less buggy than it used to be, but as of Poser 11 I've still had it occasionally nuke hours of work due to corrupting the file. The last time, I had ten figures, all dressed and posed.

I ended up going through the CR2 in a text editor, and removing all the calls to external morphs. The file opened then. The figures were all in their default settings, so I had to re-create all the characters, but it was better than having to dress and pose them all again.