[Plugin: W3 Total Cache] Minify breaking site, stylesheet & javascript not included in header

Hi everybody..
Got W3 Total Cache running on several sites (until today) without any problem.. I just love it!

On a new site the minifying isn’t working.
The link to the minified stylesheet and javascripts are not included in the theme header. While the references to the original styles and javascripts are being removed, the reference to W3 Total Cache minified files are just missing..

Don’t know where tot start to find out what’s happening. Also on the forum I didn’t find a solution or same problem.

Any suggestions are highly appreciated!
Thanks in advance!

Problem can be seen here:
Here’s the result of my compatibility check:
http://vloerverwarmingaanleggen.info/?w3tc_preview=1

Plugin Version: 0.9.2.4
PHP Version: 5.2.17 (PHP5 required for Minify, Rackspace CloudFiles, Microsoft Azure support)
Web Server: Apache
FTP functions: Installed (required for Self-hosted (FTP) CDN support)
Multibyte String support: Installed (required for Rackspace Cloud Files support)
cURL extension: Installed (required for Amazon S3, Amazon CloudFront, Rackspace CloudFiles support)
zlib extension: Installed (required for compression support)
Opcode cache: Not installed
Memcache extension: Not installed
HTML Tidy extension: Not installed (required for HTML Tidy minifier suppport)
Mime type detection: Not installed (required for CDN support)
Hash function: Installed (hash) (required for NetDNA purge support)
Safe mode: Off
Open basedir: Off
zlib output compression: Off
set_time_limit: Available
mod_deflate: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_env: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_expires: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_headers: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_mime: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_rewrite: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
mod_setenvif: Not detected (required for Page Cache (enhanced mode) and Browser Cache)
WordPress Resources

/home/sitename/www/.htaccess: OK
/home/sitename/www/wp-content: OK
/home/sitename/www/wp-content/uploads/2012/02: OK
Fancy permalinks: /%postname%/
WP_CACHE define: Defined (true)
URL rewrite: Enabled
Network mode: No

http://wordpress.org/extend/plugins/w3-total-cache/