I had tried to install Iscan the other day, but I think
I got a corrupted data file. I tried again, and it installed, but now I have a
different problem. Simple Scan and Iscan now detect my V500 as an Epson
(unknown model) and the cannot talk to it. (The good news is that they work
with the network-connected Photosmart 2610 all-in-one.)

If I try to run xsane, it also sees the V500 as an unknown Epson, and it balks
over permissions for an epkowa emulator. Running xsane as root brings up a dire
warning, but the scanner is properly detected as an Epson V500, and it works!
I'm still researching the permissions issue.