kmail from kde-4.6.1 cannot access kwallet or mysql error

[Petrus de Calguarium]

When I start kmail, kwallet opens, but I am asked for the passwords for all of 
the stored pop3 servers anyway, then after entering them (even though they are 
already in kwallet), a new window opens stating that akonadi is not running as 
root and that there are errors in the mysql log (I cannot find that log: 
/var/log/mysqld.log is completely empty) and when I then click that window 
closed, kmail also closes, with the result that I am unable to download/read my 
emails.