kde device notifier won't let disk go

[curmudgeon]

I have a hard drive in an external (usb) caddy.

When the drive was connected, the partitions popped up in the device notifier, and I was able to mount and use them.

When it came time to unmount the disk though, I was unable to unmount any of them through the device notifier. When I try, I get this message:

"Could not unmount the following device:
foo
One or more files on this device are open within an application"

I couldn't find anything with lsof or fuser, so I tried unmounting the partitions as root from a shell, and that worked with no complaints (and if there was a file in use, umount would have complained).

So I disconnected the hard drive, hoping that the filesystems would disappear from the device notifier (they did not :( ).

When I reconnected the drive, it received a different letter. The old entries are still there, and I can not mount anything with the device notifier. It provides no feedback at all, but in dolphin (which does at least recognize that the filesystems are not mounted), I get:

"An error occurred while accessing 'foo', the system responded: An unspecified error has occurred: Not authorized to perform operation"

Is there any way (short of logging out - which is not feasible at the present time) to reset all of this (ie. tell kde to rescan the devices, so it will see what is actually there and what is not)?