How reliable is Google 1+ callback function

Just try to use 1+ to unlock content

[jetteroheller]

<g:plusone callback=gp1cb></g:plusone>

and in the javascript

gp1t=new Array();

function gp1cb(gp1v)
{
alert(gp1v.href);
gp1t[gp1v.href]=gp1v.state;
}

Sometime it works, sometime it does not work.

I can not find anything wrong.

I give a plus 1, and sometimes the callback function is not called
I take a plus 1, and sometimes the callback function is not called
but the 1+ button count reacts on my action.

[jetteroheller]

Load sequence matters!

All my successfull tests had been with 1+ buttons
rendered by javascript on demand

This means I created them after the web site was loaded

All unsuccessfull tests had been with buttons built into the page

Now I moved function gb1cb used for the callback parameter
into the head section of the page. Now it works like expected