Hello! First, many thanks for the effort on new version 2.7.
Since I updated to 2.7 stable, I found lighttpd (PHP5 + FastCGI) record the following error into error.log for every access on wordpress homepage (the page could be displayed as usual, lighttpd just record such error):
POST-request, but content-length missing -> 411
But for 2.6.5, everything is ok.
After checking the time stamp in error.log, I found that is an access to wp-cron.php at the same time. Wish this information is useful. Best wishes.