Apache mod_deflate doesn't compress although logfile says it would - apache2

Question

I tried googling this by hard but was unsuccessful so far.
I've got an apache 2.2.16 on Debian with mod_deflate loaded and enabled like this:
LoadModule deflate_module /usr/lib/apache2/modules/mod_deflate.so
and
AddOutputFilterByType DEFLATE text/html text/css text/javascript application/x-javascript
DeflateFilterNote Input instream
DeflateFilterNote Output outstream
DeflateFilterNote Ratio ratio
LogFormat '"%r" %{outstream}n/%{instream}n (%{ratio}n%%) "%{User-agent}i"' deflate
CustomLog /var/log/apache2/deflate_log deflate env=!trash
When I open a page the log file says that it's compressing my CSS file (and others):
"GET / HTTP/1.1" -/- (-%) "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.17) Gecko/20110420 Firefox/3.6.17"
"GET /www/js/dojoToolkit/dijit/themes/claro/claro.css HTTP/1.1" 17244/118618 (14%) "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.17) Gecko/20110420 Firefox/3.6.17"
"GET /www/css/basis-min.css HTTP/1.1" 10877/61154 (17%) "Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.17) Gecko/20110420 Firefox/3.6.17"
But Firebug and also Chrome do still get the uncompressed files, although the explicitly accept gzip and deflate encoding.
One interesting fact is also that the
Vary: Accept-Encoding
header is still set, unlike the Content-Encoding:
GET /www/js/dojoToolkit/dijit/themes/claro/claro.css HTTP/1.1
Host: www.getabstract.com
User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.2.17) Gecko/20110420 Firefox/3.6.17
Accept: text/css,*/*;q=0.1
Accept-Language: en-us,de-ch;q=0.5
Accept-Encoding: gzip,deflate
Accept-Charset: ISO-8859-1,utf-8;q=0.7,*;q=0.7
Keep-Alive: 115
Connection: keep-alive
Referer: http://www.getabstract.com/
Cookie: __utma=73758084.1377620539.1310985055.1310989511.1310990668.3; __utmz=73758084.1310985055.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none); fpc10001731534234=Y63gTWM9|aCXc2doLaa|fses10001731534234=|aCXc2doLaa|Y63gTWM9|fvis10001731534234=Zj1odHRwJTNBJTJGJTJGd3d3LmdldGFic3RyYWN0LmNvbSUyRiZiPUhvbWVwYWdlJTIwRU4=|8M8Y7oT7YH|8M8Y7oT7YH|8M8Y7oT7YH|8|8M8Y7oT7YH|8M8Y7oT7YH; __ar_v4=262MD4C3UNHKBELB3VUEGS%3A20110717%3A20%7CTBE3U4YYEBCGHJ2QAUBVE4%3A20110717%3A20%7CXVIJYAN7KFDQXPECC3AI7E%3A20110717%3A20; JSESSIONID=abcKrMR5EVQv68Os6h9et; __utmc=73758084
Pragma: no-cache
Cache-Control: no-cache
Response:
HTTP/1.1 200 OK
Date: Mon, 18 Jul 2011 13:54:45 GMT
Server: Apache
Last-Modified: Wed, 04 May 2011 10:49:12 GMT
Etag: "28023a-1cf5a-4a27101cc1a00"
Accept-Ranges: none
Cache-Control: max-age=600
Expires: Mon, 18 Jul 2011 14:04:45 GMT
Vary: Accept-Encoding
Content-Length: 118618
Keep-Alive: timeout=15, max=99
Connection: Keep-Alive
Content-Type: text/css
Any ideas?
Thanks in advance.
Marc

Answer 1

Long shot: is apache treating your css file correctly - i.e. are the mime types configured correctly?
Where is your output filter set, in an included config or in an .htaccess [check that .htaccess is allowed to override]
Can you remove the filter & see if it will compress all content?
Lastly - is there a public URL we can test?
-sean
EDIT:
Hi Again, what are you using to test locally? I can see the correct content encoding in firefox/firebug/yslow. - [I also see several other issues] - if you are not using firebug, I suggest checking it out [strongly!] - but otherwise, yes, it appears your compression is working correctly.
-sean