It may be one of the other clouds. I am trying to narrow it down.
I also have Nuance Cloud drive, which is really the Gladinet "integrator" that also handles box.net and Windows Live SkyDrive.
This mounts itself as a networked drive in DOpus.
I also have PaperPort Anywhere, a rebadged OfficeDrop toy that Nuance sells with PaperPort.
So here is plenty of room for something to screw up DOpus.