Can't Create Cache

Hello,

first posting here, so "Hello" to everyone...
I guess it's a frequently asked question, but I was not able to find 
any solution with google.

I am trying to install sqwebmail on the company server. It's working 
fine on my private one, so it's a little bit annoying .. :) I tried 
both 3.6.2 and 4.0.x - but I am getting the same error message:

Error:
After successfully login in, any try to open a folder is giving me 
this error message:
"Can't create cache file."
(see screenshot http://www.stonki.de/sqwebmail.jpg)

/var/log/messages:
Mar 25 14:33:09 webserver sqwebmaild: Can't create cache file 
|./tmp/1080225189.M558352P19457_sqwebmail-db.webserver|: No such 
file or directory

BUT (!):
webserver:~ # ls 
-als /home/vpopmail/domains/xxxxxx.com/stefan.onken/Maildir/tmp/
total 8
   4 drwx------    2 vpopmail vchkpw       4096 Mar 25 14:33 .
   4 drwx------   10 vpopmail vchkpw       4096 Mar 25 12:33 ..
   0 -rw-------    1 vpopmail vchkpw          0 Mar 25 14:33 
1080225189.M558352P19457_sqwebmail-db.webserver

So its there....

Configure Optionen:
./configure --prefix=/usr/local/share/sqwebmail4/ 
--with-cachedir=/var/cache/sqwebmail4/ --disable-changepass 
--enable-cgibindir=/srv/www/cgi-bin/ 
--enable-imagedir=/srv/www/htdocs/mailadmin.xxxxxxxx.net/icons/ 
--enable-imageurl=http://mailadmin.xxxxxxx.net/icons/ 
--without-authdaemon --with-db=gdbm

Thanks !

Stefan

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