Kobo: Error communicating with device

The error message:

calibre, version 0.8.64
ERROR: Error: Error communicating with device

database disk image is malformed

Traceback (most recent call last):
File "site-packages/calibre/gui2/device.py", line 83, in run
File "site-packages/calibre/gui2/device.py", line 405, in _books
File "site-packages/calibre/devices/kobo/driver.py", line 299, in books
DatabaseError: database disk image is malformed

I'm not sure how to fix this. It was working before I updated to 0.8.64, and I think I was using the immediatly previous version.

I'm running Debian 6 stable ("squeeze"). The OS recognizes the Kobo and the Kobo reader device pugin is green.

Does anyone have any ideas?

[Later]
A factory reset fixed the issue. Not what I wanted to do, but what the heck.