First of all, Merry Xmas
But I bring bad news...I gifted a Kindle 4 to my mom and it has the same problems on both computers, just like my PW...so, I should think that the problem still on Calibre software. Interface plug-in, maybe?
I really don't know, but I'm a bit burned out of this...
PD: BIG GREAT NEWS! I tried changing book format manually (right-click on book > convert book individually) and then I could send it to PW! No 0 of 1 books anymore!
But....why the convert & send books window doesn't work?