When I plug in my PRS ereader starts automatically so I deleted the Sony ereader on my computer, then started Caibre and plugged in my PRS. Same response, PRS indicates a connection but Calibre says no unit is plugged in so I re-installed Sony ereader. I have a work around for now which gets my books on the reader:
1. Convert the books I want to PRS format.
2. Use Calibre to save only the PRS books to a new folder, close Calibre.
3. Start Sony ereader locate the new books in the directory I just saved them to.
4. Move the books to my reader.
Yes, I know Calibre would be so much better but if I can't get it to work this is the only way I can get my reading done.
I'll keep looking for a way to get the Calibre to see my PRS in the meantime.