I use the CB Juice 2 v3.1.6 between Joomla 2.5, CB 1.9.1 (export) and a Joomla 3.3.3, CB 1.9.1 (import). The exportation works and the begining of the CSV file is :
"name","username","email","password" (...)

but for the importation I have a error message :

CBJ2_HEADER_VARIABLES are
Array ( [0] => "name" [1] => username [2] => email [3] => password [4] (...)
"name" is not valid
Terminating because of undefined header variables

Can someone help me to find a solution ?
thanks and sorry for my bad english

remove quotes around "name"

wolverton wrote: remove quotes around "name"

That doesn't work. The problem was : I opened the CSV file with simple text editor and not with notepadd++

But CB juice have for my website a lot of errors.

So, to transfert the users from a website to an other :
I went in phpmyadmin and transfered the tables which beginning with joomla_user (joomla_user_profiles, joomla_user_notes...you can maybe have an other prefix like : jos_) and joomla_comprofiler (joomla_comprofiler_lists, joomla_comprofiler_plugin...)
The transfer consist to : delet these tables on the new website, export the tables in sql on the old website and import on the new website.

Not a recommended method ...

So, to transfert the users from a website to an other :
I went in phpmyadmin and transfered the tables which beginning with joomla_user (joomla_user_profiles, joomla_user_notes...you can maybe have an other prefix like : jos_) and joomla_comprofiler (joomla_comprofiler_lists, joomla_comprofiler_plugin...)
The transfer consist to : delet these tables on the new website, export the tables in sql on the old website and import on the new website.

why ?

Since it is a db hack and does not directly relate to CBJ2, we wanted to avoid recommending it. Some users might have difficulty with it. Maybe a topic for another forum category.
BTW, you might want to run Joomla 'check database' fix afterwards.