Originally Posted by Vampira
I am very interested how to sync my kobo touch via wifi though, without having to your the kobo desktop.
Exactly as Witty Username says. The "sync icon" is the one with the circled arrows in a cloud (under the cog wheel, top left of the home screen).
If that also gives you a connection error, perhaps the 10th book it's trying to sync is corrupted in some way (as you say the connection error occurs after the 9th book every time)? You could try and delete book 10 from your account (it doesn't get deleted but it goes into your archived books: it's still available but stops syncing onto your device), and see if that solves anything...