The site is an upgrade from 4.6.5 through 4.8.1 to 4.9
But a clean installation at 4.9 running on a celan/empty set of tables, using same configuration.php does give the same error.

I also tried the configuration_sample.php, of course i changed the appropiate database parameters, it still gives the same warning.

I have tried to read this forum but I  can not find any hints o get pass this warning.
Anyone got an idea?

Below is the system info, from the administration module.
PHP built On:        Linux srv22 2.6.18-6-vserver-amd64 #1 SMP Thu Nov 5 03:56:56 UTC 2009 x86_64
Database Version:     5.0.32-Debian_7etch11-log
PHP Version:     5.3.1
Web Server:     Apache
WebServer to PHP interface:     cgi-fcgi
MiaCMS Version:     MiaCMS 4.9.0 Stable [ saigo ] 2009-07-11 00:00 GMT
User Agent:     Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2) Gecko/20100115 Firefox/3.6 GTB6
Relevant PHP Settings:    
Safe Mode:     OFF
Open basedir:     /customers/ct-data.dk/ct-data.dk:/var/www/diagnostics:/usr/share/php
Display Errors:     ON
Short Open Tags:     ON
File Uploads:     ON
Magic Quotes:     OFF
Register Globals:     ON
Output Buffering:     OFF
Session save path:     /customers/ct-data.dk/ct-data.dk/tmp
Session auto start:     0
XML enabled:     Yes
Zlib enabled:     Yes
Disabled Functions:     disk_total_space, diskfreespace, exec, system, popen, proc_open, proc_nice, shell_exec, passthru, dl
WYSIWYG Editor:     mostlyce
Configuration File:     <?php
$mosConfig_offline = '0';
$mosConfig_host = 'xxxxxx'
$mosConfig_user = 'xxxxxx'
$mosConfig_password = 'xxxxxx'
$mosConfig_db = 'xxxxxx'
$mosConfig_dbprefix = 'mia01_';
$mosConfig_absolute_path = '/customers/ct-data.dk/ct-data.dk/httpd.www/miacms/';
$mosConfig_live_site = 'http://www.ct-data.dk/miacms';
$mosConfig_sitename = 'Odense Salsa Forening';
$mosConfig_shownoauth = '0';
$mosConfig_user = 'xxxxxx'
$mosConfig_uniquemail = '0';
$mosConfig_usecaptcha = '0';
$mosConfig_offline_message = 'This site is down for maintenance.
Please check back again soon.';
$mosConfig_error_message = 'This site is temporarily unavailable.
Please notify the System Administrator';
$mosConfig_debug = '0';
$mosConfig_lifetime = '900';
$mosConfig_MetaDesc = 'Odense Salsa Forening OSaF';
$mosConfig_MetaKeys = 'Salsa Odense ';
$mosConfig_MetaAuthor = '1';
$mosConfig_MetaTitle = '1';
$mosConfig_lang = 'danish';
$mosConfig_locale = 'da_DK';
$mosConfig_charset = 'utf-8';
$mosConfig_locale_debug = '0';
$mosConfig_locale_use_gettext = '0';
$mosConfig_offset = '0';
$mosConfig_hideAuthor = '1';
$mosConfig_hideCreateDate = '1';
$mosConfig_hideModifyDate = '1';
$mosConfig_hidePdf = '1';
$mosConfig_hidePrint = '0';
$mosConfig_hideEmail = '0';
$mosConfig_enable_log_items = '0';
$mosConfig_enable_log_searches = '0';
$mosConfig_enable_stats = '1';
$mosConfig_enable_stats_charting = '';
$mosConfig_yui_loader = 'local_min';
$mosConfig_yui_version = '2.7.0';
$mosConfig_sef = '0';
$mosConfig_vote = '0';
$mosConfig_gzip = '0';
$mosConfig_multipage_toc = '0';
$mosConfig_allowUserRegistration = '0';
$mosConfig_enable_old_javascript = '0';
$mosConfig_enable_openid = '0';
$mosConfig_link_titles = '1';
$mosConfig_error_reporting = '-1';
$mosConfig_register_globals = '1';
$mosConfig_list_limit = '50';
$mosConfig_caching = '1';
$mosConfig_cachepath = '/customers/ct-data.dk/ct-data.dk/httpd.www/miacms/cache';
$mosConfig_cachetime = '900';
$mosConfig_mailer = 'mail';
$mosConfig_mailfrom = 'formand@osaf.dk';
$mosConfig_fromname = 'Odense Salsa Forening ';
$mosConfig_sendmail = '/usr/sbin/sendmail';
$mosConfig_smtpauth = '0';
$mosConfig_smtpuser = '';
$mosConfig_smtppass = '';
$mosConfig_smtphost = 'localhost';
$mosConfig_back_button = '0';
$mosConfig_item_navigation = '0';
$mosConfig_enable_revisioning = '0';
$mosConfig_revision_count = '10';
$mosConfig_secret = '4Sqq30iWBd9ooACo';
$mosConfig_pagetitles = '1';
$mosConfig_readmore = '1';
$mosConfig_hits = '0';
$mosConfig_icons = '1';
$mosConfig_favicon = 'favicon.ico';
$mosConfig_fileperms = '';
$mosConfig_dirperms = '';
$mosConfig_mbf_content = '0';
$mosConfig_helpurl = 'http://miacms.org';
?>

Here comes the php info:
PHP Version 5.3.1

System     Linux srv22 2.6.18-6-vserver-amd64 #1 SMP Thu Nov 5 03:56:56 UTC 2009 x86_64
Build Date     Feb 11 2010 17:27:30
Server API     CGI/FastCGI
Virtual Directory Support     disabled
Configuration File (php.ini) Path     /etc/php5
Loaded Configuration File     /customers/ct-data.dk/ct-data.dk/config/php5.ini
Scan this dir for additional .ini files     /etc/php5/conf.d
Additional .ini files parsed     /etc/php5/conf.d/errors.ini, /etc/php5/conf.d/magic_quotes.ini, /etc/php5/conf.d/memlimit.ini, /etc/php5/conf.d/php53.ini, /etc/php5/conf.d/sessions.ini
PHP API     20090626
PHP Extension     20090626
Zend Extension     220090626
Zend Extension Build     API220090626, NTS
PHP Extension Build     API20090626, NTS
Debug Build     no
Thread Safety     disabled
Zend Memory Manager     enabled
Zend Multibyte Support     disabled
IPv6 Support     disabled
Registered PHP Streams     https, ftps, compress.zlib, php, file, glob, data, http, ftp
Registered Stream Socket Transports     tcp, udp, unix, udg, ssl, sslv3, sslv2, tls
Registered Stream Filters     zlib.*, convert.iconv.*, string.rot13, string.toupper, string.tolower, string.strip_tags, convert.*, consumed, dechunk

An finally all  of the listed directories are writeable ...