Upgraded 12.04 to 14.04: Problems with samba and gksu

[Sascha Manns]

Hello list,

yesterday i have upgraded my office machine from Ubuntu 12.04 to Ubuntu 
14.04 and the most works fine.
Actually i've seen two problems:

1.) If i'm starting synaptic the old Ubuntu asked me for a root 
password (i think with gksu) and then it comes up. Actually it does 
nothing after clicking on the icon. The same problem is if i'm using the 
control-center. Let me say i would like to add a printer, then i can 
find it, but i can't add it to the system.
Both things (synaptic and control center) working if i'm starting it in 
the console with sudo.

2.) I have a fstab like:
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
proc            /proc           proc    nodev,noexec,nosuid 0       0
# / was on /dev/sda1 during installation
UUID=4efbcc82-0ee2-4020-866e-5b4be1650155 /               ext4    
errors=remount-ro 0       1
# swap was on /dev/sda5 during installation
UUID=e126317c-bf37-41f1-94ae-ba3909d79ee4 none            swap    sw    
          0       0

//sourcen/user    /media/sourcen/user    cifs   
iocharset=utf8,gid=sambashare,uid=smanns,credentials=/home/smanns/share/.ads_secret 
0 0
//sourcen/public  /media/sourcen/public  cifs   
iocharset=utf8,gid=sambashare,uid=smanns,credentials=/home/smanns/share/.ads_secret 
0 0
//sourcen/sourcen /media/sourcen/sourcen cifs   
iocharset=utf8,gid=sambashare,uid=smanns,credentials=/home/smanns/share/.ads_secret 
0 0
//sourcen/xprog   /media/sourcen/xprog   cifs   
iocharset=utf8,gid=sambashare,uid=smanns,credentials=/home/smanns/share/.ads_secret 
0 0
//sourcen/daten   /media/sourcen/daten   cifs   
iocharset=utf8,gid=sambashare,uid=smanns,credentials=/home/smanns/share/.ads_secret 
0 0

The .ads_secret file is also on the right place with the right content. 
I've pasted my smb.conf there: http://paste.ubuntu.com/10390248/
A restart of samba on the console gives me:
smanns at MYKSMANNS:/media/sourcen$ sudo service smbd restart
smbd stop/waiting
smbd start/running, process 18806

So it looks like a right start.

Actually all directories under /media/sourcen/* are empty. So it looks 
like the mount hasn't mounted the cifs.

Maybe anyone can give me the hint for fix this?

-- 
Yours sincerly

Sascha Manns