Comment 2 for bug 617656

Hmm... when I do that, I get more useful data. Could you try installing gnome-dbg and seeing if that improves the backtrace any? Otherwise, can you build the client and «sudo cp nautilus/.libs/libnautilus-ubuntuone.{a,la,so} /usr/lib/nautilus/extensions-2.0/ && killall nautilus» and try again?
Rodrigo would know this stuff by heart, but he's on vacation until Tuesday and I'd rather know what's going on before that :)