I don’t think it is restricted to being just plugins.
The admin system since upgrading to 3.6.1 runs too slow to use (3-5 mins response between clicks) and the PHP error log has this in it…
[19-Sep-2013 17:41:13 UTC] PHP Warning: stream_get_contents(): SSL: An existing connection was forcibly closed by the remote host.
in C:\inetpub\wwwroot\wp-includes\class-http.php on line 985
I am using multisite , and have the wp-config set to force admin SSL, but I also run WP on IIS7 so have a valid SSL certificate installed and applied to the admin part of wordpress.
There appears to be something very wrong with the latest 3.6.x versions of wordpress and SSL.