I have received a response from the SU team; they were able to reproduce the error and comfirmed the bug:
"Thank you for your note. I've opened your file and was able to reproduce
the crash when draping on the two scenerios you provided where the drape
was onto exploded geometry. When draping onto a grouped surface it would
work fine and if I grouped the geometry on your two "exploded target"
sections those would also drape fine. The issue seems to be specific to
what you're draping on and whether or not its a group when I perform the
operation in SketchUp 8."
It seems to me that if you group the "target" object it helps... sometimes.