[Greasemonkey] User scripts don't work at a certain site?

[Chris Beams]

All,

I¹m putting together a user script for http://center.spoke.com, however I
can¹t seem to get even the simplest user script to run there.  It¹s as if
greasemonkey functionality had been disabled for that domain.

For example, the following user script would/should clearly work on any
site:

// ==Userscript==
// @name                Super basic
// @description        Simply logs "hello world!" to the JS console
// @include             *

GM_log("hello world!");

// ==/Userscript==

... And this script does work on every site I¹ve tried it on, with the
exception of http://center.spoke.com.  Bizarre!

I¹m fairly new to greasemonkey, perhaps I¹ve missed something big, but it
feels like this is something a little more subtle.  I¹d very much appreciate
anyone¹s help!

- Chris