QuiteInsane won't scan after kernel update

QuiteInsane is the SANE (scanner) plugin used by GIMP. I recently did an update of various things, including a kernel update, using Adept. Now, QuiteInsane gives me errors when I want to scan.

Here are things I have learned when diagnosing it:

- All of this worked well enough before the update.
- "lsusb" sees it as this: Bus 006 Device 005: ID 04b8:0122 Seiko Epson Corp.
- If I plug a thumbdrive into the USB port, it works just fine.
- The scanner works fine when connected to another computer (WinXP).
- Power cycling the scanner and unplug/replug the USB don't help.
- If I run GIMP from the command line, here's what I see on stdout/stderr:

[snapscan] Cannot open firmware file /usr/share/sane/snapscan/your-firmwarefile.bin.
[snapscan] Edit the firmware file entry in snapscan.conf.

To my knowledge, there is no firmware needed for this scanner.

Note that there is no /usr/share/sane/snapscan directory on my system. The one related, /usr/share/sane/gt68xx (whatever that is), is empty.

Here is the sequence of events I observe:

- From the GIMP main window, I select File > Acquire > QuiteInsane > Scan...
- I get a small window, title "SANE Message", message "Unknown error." I click OK.
- I get a "QuiteInsane-Plugin" window that lets me select the device. I select the Epson and click "Select device".
- I get another of the same "Unknown error" boxes, and that's it.