Most of the conversions worked great, everything seems to be there.

But I have encountered some problems, first the hashed passwords haven´t been copied correctly it seems, but that´s not my main concern as it can always be fixed manually, or by reseting the password. The biggest problem is that you can´t register a new account any longer. You fill in the form and after you hit register you directly jumps to the login page with the error message "Incorrect username and/or password". And nothing is saved in the user table. (the Verify registrations option isn´t activated)

Any idea of what could be the problem? (Otherwise a great tool)

Think I have located the problem with the register, obviously it had nothing to do with this tool. Sry for that.
The password hashes is a bit strange tho, it doesn´t work with the passwords copied from the phpbb(3) table, but If I take the passwords from an older installation with phpbb2 it works.