Device notifier doesn't detect devices

[Brad Alexander <storm16@gmail.com>]

In the past couple of weeks, I have noticed that the device notifier has stopped detecting usb devices I plug in to my workstation, including my Nokia N900's internal drive and the external SD, and my Hitachi 500GB usb drive. They are getting picked up by the system:

Mar  3 19:11:44 defiant kernel: : [1174998.005494] sd 32:0:0:0: [sdb] 56631296 512-byte logical blocks: (28.9 GB/27.0 GiB)
Mar  3 19:11:44 defiant kernel: : [1174998.005858] sd 32:0:0:0: [sdb] Assuming drive cache: write through
Mar  3 19:11:44 defiant kernel: : [1174998.007104] sd 32:0:0:0: [sdb] Assuming drive cache: write through
Mar  3 19:11:44 defiant kernel: : [1174998.011253]  sdb:
Mar  3 19:11:47 defiant kernel: : [1175001.008871] sd 32:0:0:1: [sdc] 31116288 512-byte logical blocks: (15.9 GB/14.8 GiB)
Mar  3 19:11:47 defiant kernel: : [1175001.009362] sd 32:0:0:1: [sdc] Assuming drive cache: write through
Mar  3 19:11:47 defiant kernel: : [1175001.010860] sd 32:0:0:1: [sdc] Assuming drive cache: write through
Mar  3 19:11:47 defiant kernel: : [1175001.013386]  sdc: sdc1

but the device notifier says "No devices plugged in."

I haven't done anything to the system other than routine aptitude upgrades. I'm running kde 4.4.5, the current from sid.

Anyone got any ideas where to look?

Thanks,
--b