I can't access an folder - you have unknown permissions

After the update to Mountain Lion, i can't access a folder insider my home-folder any more;

First I tried Apple+i ... you have unknown permissions ... nothing to unlock; nothing to change

... then i tried to repair the permissions; without luck.

Then i saw in the terminal (ls -l), that the group was different; although the owner was right.

I chown -R the folder to alex:staff; (also chmod -R 755)

now it's:

drwxrwxr-x@ 44 alex staff 1496 15 Okt 00:28 ALEXKERN <--- THIS IS THE FOLDER

drwxr-xr-x 752 alex staff 25568 15 Okt 00:07 Abbilden

drwxr-xr-x 5 alex staff 170 15 Nov 2011 Austausch

drwxrwxrwx 333 alex staff 11322 15 Okt 00:25 Behalten

drwxr-xr-x 15 alex staff 510 31 Aug 15:31 Benötigen

drwxrwxrwx 28 alex staff 952 9 Feb 2012 Benutzen

drwxr-xr-x 8 alex staff 272 8 Feb 2012 Comics

drwx------+ 169 alex staff 5746 17 Okt 21:09 Desktop

drwx------+ 14 alex staff 476 15 Okt 14:55 Documents

drwx------+ 55 alex staff 1870 17 Okt 16:13 Downloads

drwxr-xr-x@ 48 alex staff 1632 17 Okt 20:16 Downloads_J

(...)

all other folders are normal accessible

ls ALEXKERN gives me: ALEXKERN: Permission denied

sudo ls -l ALEXKERN works of course:

drwxr-xr-x 7 alex staff 238 23 Nov 2011 0 NEW WORLD ORDER

drwxr-xr-x 5 alex staff 170 7 Sep 13:32 1 Rechnungen

drwxr-xr-x+ 4 alex staff 136 14 Feb 2012 2 Fotos von Freunden

drwxr-xr-x 23 alex staff 782 9 Feb 2012 2 unsortierbare Fotos

(...)

Did i miss something?

???

:-) AK