Did you change version of ADE recently?
Which Kobo?
Sometimes authorization gets confused. May be worth deauthroizing and reauthorizing.
For ADE, ctrl-shift-D, restart ADE and reauthorize.
For Kobo, ctrl-shift-E when running ADE with Kobo plugged in, restart and reauthorize.
Sometimes the authorization goes even more wrong and it is necessary to delete some files on the Kobo;
try the others first and post back if they don't help, and I'll check more details.
