Error halted execution

[susfour]

SD has been running great. Over the weekend, I was using my PB to test another external FW drive that was giving me grief on another workstation. Since then, my nightly SD smart updates have failed with this log:

|07:43:30 AM|Error| ditto: /Volumes/Big D/usr/X11R6/bin/.BC.u6b5vd: Invalid argument
[***] Tuesday, September 06, 2005 08:18:30 AM America/Chicago
|08:18:31 AM|Info| SuperDuper!, version 74, path: /Applications/SuperDuper!.app, OS: 10.3.9 (7W98)
|08:18:31 AM|Info| Source Drive: /, name: Ginger's HD, device: /dev/disk0s10 type: hfs, OS: 10.3.9 (7W98), capacity: 74.43 GB, used: 32.96 GB, directories: 63552, files: 370758
|08:18:31 AM|Info| Target Drive: /Volumes/Big D, name: Big D, device: /dev/disk1s10 type: hfs, OS: N/A, capacity: 0.00 GB, used: 0.00 GB, directories: 0, files: 0
|08:18:31 AM|Info| Copy Mode : Smart Update
|08:18:31 AM|Info| Copy Script : Backup - all files.dset
|08:18:31 AM|Info| Transcript : BuildTranscript.plist
|08:18:31 AM|Info| PHASE: Volume Preparation
|08:18:31 AM|Info| ...ACTION: Enable Permissions
|08:18:31 AM|Info| ......COMMAND => Enabling permissions on Ginger's HD
|08:18:31 AM|Info| Refreshing Disk Arbitration ...
|08:18:31 AM|Info| ......COMMAND => Verifying that permissions are enabled for Ginger's HD
|08:18:32 AM|Info| Permissions on '/' are enabled.
|08:18:32 AM|Info| ......COMMAND => Enabling permissions on Big D
|08:18:32 AM|Info| Refreshing Disk Arbitration ...
|08:18:32 AM|Error| vsdbutil: Couldn't get volume information for '/Volumes/Big D': Device not configured

What might have happened?