Piwiki 1.8.3 Login only for administrative user possible

Hi @all,
I already posted this issue in the German forum but no one answered :(.
I am using the latest version 1.8.3 of Piwik at our server. The problem is that the created users - except the admin one - can not login to the system. The error message is:
Error: Username & Password not correct
I re-did this process several times but it won’t work.
Is there any log file? A switch to activate debug messages or something similar?
I tried several browsers like FF, IE, Chrome and Opera but nothing changed.
Cookies are allowed.
What else can be the problem?
Which additional information do you need from my side to help?
The newly created user is allowed to log in and see the stats for all defined pages.

Thank you in advance.

My 1.8.3 works just fine. Two things to consider:

[li] Usernames are case sensitive (mine are all lowercase and tablets, etc do autocorrect and change the casing)
[/li][li] You need to give them access to at least one site in the “Manage Access” section above (the first column is “no access” and for some strange reason I would excpect the order different and get it wrong most of the time if I don’t read proper the heading)

Problem solved :(.
Typical problem-in-front-of-screen problem. The file used to store the password contained a space at the end of the password and some browsers add one or two spaces when copy+pasting text from one window to another.
Sorry for stealing your time.
Shame on me!:S