I know very well the difference between shell and ftp users.
I'm having problem with both of them on all newly created clients (except the first one that was created after initial installation of the ispconfig).
I will enable debug on pure-ftpd, but what about with the shell's users problem. You understand that this problem makes ispconfig useless.
I will enable debug on ispconfig and report but if something useful appears.
It is a major problem and i think it happened after the update to 188.8.131.52. My system is useless as it is now so that's why i'm eager to find a solution.
Regarding ftp users i have recreated the user (and several others) multiple times but always i'm getting a wrong password error.