Hey Kovid, thought you were on vacation!
Yes, Ubuntu mounts it as "reader" and also as the install directory for Sony's reader software.
However, I booted up vmware and had windows repair my device's drives. Not sure what happened to them, but everything seems to be working now.
I have no clue how all this came about. Something went screwy somewhere.
I think what I'll do is just run under windows for the time being using the latest install. I was using an older version through synaptic on the Ubuntu side.