Hello Ulrich,
first of all, thank you for the great plugin. It seemed to work smoothly: I've exported my users from one blog (fortunately, there are only about 10 of them) and imported them successfully into another one. Of course, since passwords are hashed in DB, I couldn't import them so left them blank in import .csv file - I though I'd be able to use "remind my passwword" feature to set new password. The problem is, that the link in e-mail sent automatically by WP seems to be invalid - I get error "invalid key".
Am I doing something wrong ? I don't see any other possibility to import existing users to that second blog.
Do you have any idea what can be wrong ? Thank you in advance.