Re: piwik hiding footprint not working?

Piwik Proxy Hide URL script just works fine for me.

However, I need to set some custom variables but It seems it doesn't work when "pushed" on javascript event.

When I use the Piwik Proxy Hide URL script, I can't catch custom variable trigged by a javascript event.
e.g (using jQuery) :

$('#block').on('click', 'span', function(){
			_paq.push(["setCustomVariable", 1, "myVariable", $(location).attr("href"), "page"]);
			_paq.push(['trackPageView']);
		});

trackPageView does catch the custom variable. If I take a look at the http request, the javascript click event did append the custom variable as a GET parameter, but then nothing happens. It's like the custom variable is ignored and skipped from DB.

It will work fine if I reverse to the "no proxy" async loading (just switching to the "real" piwik server url and piwik.php to piwik.js)
Any help ?