GlassFish Authentication Failed

I need some help.
I'm new to GlassFish and I followed this tutorial (http://www.nabisoft.com/tutorials/glassfish/installing-glassfish-311-on-...) to install a GlassFish server on my ubuntu 10.04 server. But instead of GlassFish 3.1.1 I used GlassFish 3.1.2.2 and java 7 update 21.

No I'm facing the problem that I get always the message "Authentication Failed Re-enter your username and password" when I try to login to the admin console.

Log:

[#|2013-04-22T00:44:26.852+0200|INFO|glassfish3.1.2|
javax.enterprise.system.tools.admin.com.sun.enterprise.container.common|
_ThreadID=85;_ThreadName=Thread-2;|
User [admin] from host localhost.localdomain does not have administration access|#]

[#|2013-04-22T00:44:26.855+0200|WARNING|glassfish3.1.2|
org.apache.catalina.connector.Request|_ThreadID=84;_ThreadName=Thread-2;|
PWC4011: Unable to set request character encoding to UTF-8 from context ,
because request parameters have already been read, or
ServletRequest.getReader() has already been called|#]

I tried to enalbe secure admin with
asadmin --host localhost --port 4848 enable-secure-admin
but without success.

Any ideas?
Thanks a lot!