Hello,
No, it’s not a twitter problem (otherwise it would affect a lot of website that use twitter button).
It’s a problem on your machine.
Here is the result on a “clean” server :
HTTP/1.0 200 OK
Cache-Control: no-cache
Last-Modified: Thu, 19 Sep 2013 23:54:42 GMT
ETag: “86e25ce34214e039e32bd33c7aaeefa6”
Content-Type: text/html; charset=utf-8
Date: Sun, 22 Sep 2013 18:54:06 GMT
Connection: close
P3P: CP=”CAO DSP LAW CURa ADMa DEVa TAIa PSAa PSDa IVAa IVDa OUR BUS IND UNI COM NAV INT”
