After updating my google and bing webmaster info dashboards I noticed that my dokuwiki sites deliver the sitemap.xml.gz compressed twice, the result of this being that the sitemaps show up empty in Bing (Google seems to be able to cope).
There appears to be a second compression taking place as the file is transferred which shouldn't happen IMHO, the file generation in the cache is OK, ie. when i retrieve it using ftp the file is correct but downloading it using the browser it is saved to disk being compressed twice. To get the xml I need to uncompress it twice. (this is on Windows XP using Chrome 21 and Firefox 14)
browser response headers (for
http://wild-water.nl/dokuwiki/?do=sitemap):
Cache-Control:no-store, no-cache, must-revalidate, post-check=0, pre-check=0
Content-Disposition:attachment; filename=sitemap.xml.gz
Content-Encoding:gzip
Content-Length:3306
Content-Type:application/x-gzip
Date:Sun, 05 Aug 2012 12:17:35 GMT
ETag:"5d12f408c6012496092a3ba709262d1b"
Expires:Thu, 19 Nov 1981 08:52:00 GMT
Last-Modified:Thu, 02 Aug 2012 23:42:58 GMT
Pragma:no-cache
Server:Microsoft-IIS/6.0
Vary:Accept-Encoding
X-Powered-By:ASP.NET
example/affected sitemaps and server info:
http://wild-water.nl/dokuwiki/?do=sitemap (win32, IIS/6.0, php 5.3.8, cgi-fcgi)
http://dokuwikispatial.sourceforge.net/dokuwiki?do=sitemap (CentOS, Apache/2.2.3, php 5.3.2, apache2handler)
http://www.hooidonksekanoclub.nl/dokuwiki/?do=sitemap (Linux, Apache, php 5.2.4-2ubuntu5.24, cgi-fcgi)