Solved this, the problem was using this. As IE sucks, you need to use $(this) so here is the final code:
(function(a){a.tools=a.tools||{version:"v1.2.5"},a.tools.tooltip={conf:{effect:"toggle",fadeOutSpeed:"fast",predelay:0,delay:30,opacity:1,tip:0,position:["top","center"],offset:[0,0],relative:!1,cancelDefault:!0,events:{def:"mouseenter,mouseleave",input:"focus,blur",widget:"focus mouseenter,blur mouseleave",tooltip:"mouseenter,mouseleave"},layout:"<div/>",tipClass:"tooltip"},addEffect:function(a,c,d){b[a]=[c,d]}};var b={toggle:[function(a){var b=this.getConf(),c=this.getTip(),d=b.opacity;d<1&&c.css({opacity:d}),c.show(),a.call()},function(a){this.getTip().hide(),a.call()}],fade:[function(a){var b=this.getConf();this.getTip().fadeTo(b.fadeInSpeed,b.opacity,a)},function(a){this.getTip().fadeOut(this.getConf().fadeOutSpeed,a)}]};function c(b,c,d){var e=d.relative?b.position().top:b.offset().top,f=d.relative?b.position().left:b.offset().left,g=d.position[0];e-=c.outerHeight()-d.offset[0],f+=b.outerWidth()+d.offset[1],/iPad/i.test(navigator.userAgent)&&(e-=a(window).scrollTop());var h=c.outerHeight()+b.outerHeight();g=="center"&&(e+=h/2),g=="bottom"&&(e+=h),g=d.position[1];var i=c.outerWidth()+b.outerWidth();g=="center"&&(f-=i/2),g=="left"&&(f-=i);return{top:e,left:f}}function d(d,e){var f=this,g=d.add(f),h,i=0,j=0,k=d.attr("title"),l=d.attr("data-tooltip"),m=b[e.effect],n,o=d.is(":input"),p=o&&d.is(":checkbox, :radio, select, :button, :submit"),q=d.attr("type"),r=e.events[q]||e.events[o?p?"widget":"input":"def"];if(!m)throw"Nonexistent effect \""+e.effect+"\"";r=r.split(/,\s*/);if(r.length!=2)throw"Tooltip: bad events configuration for "+q;d.bind(r[0],function(a){clearTimeout(i),e.predelay?j=setTimeout(function(){f.show(a)},e.predelay):f.show(a)}).bind(r[1],function(a){clearTimeout(j),e.delay?i=setTimeout(function(){f.hide(a)},e.delay):f.hide(a)}),k&&e.cancelDefault&&(d.removeAttr("title"),d.data("title",k)),a.extend(f,{show:function(b){if(!h){l?h=a(l):e.tip?h=a(e.tip).eq(0):k?h=a(e.layout).addClass(e.tipClass).appendTo(document.body).hide().append(k):(h=d.next(),h.length||(h=d.parent().next()));if(!h.length)throw"Cannot find tooltip for "+d}if(f.isShown())return f;h.stop(!0,!0);var o=c(d,h,e);e.tip&&h.html(d.data("title")),b=b||a.Event(),b.type="onBeforeShow",g.trigger(b,[o]);if(b.isDefaultPrevented())return f;o=c(d,h,e),h.css({position:"absolute",top:o.top,left:o.left}),n=!0,m[0].call(f,function(){b.type="onShow",n="full",g.trigger(b)});var p=e.events.tooltip.split(/,\s*/);h.data("__set")||(h.bind(p[0],function(){clearTimeout(i),clearTimeout(j)}),p[1]&&!d.is("input:not(:checkbox, :radio), textarea")&&h.bind(p[1],function(a){a.relatedTarget!=d[0]&&d.trigger(r[1].split(" ")[0])}),h.data("__set",!0));return f},hide:function(c){if(!h||!f.isShown())return f;c=c||a.Event(),c.type="onBeforeHide",g.trigger(c);if(!c.isDefaultPrevented()){n=!1,b[e.effect][1].call(f,function(){c.type="onHide",g.trigger(c)});return f}},isShown:function(a){return a?n=="full":n},getConf:function(){return e},getTip:function(){return h},getTrigger:function(){return d}}),a.each("onHide,onBeforeShow,onShow,onBeforeHide".split(","),function(b,c){a.isFunction(e[c])&&a(f).bind(c,e[c]),f[c]=function(b){b&&a(f).bind(c,b);return f}})}a.fn.tooltip=function(b){var c=this.data("tooltip");if(c)return c;b=a.extend(!0,{},a.tools.tooltip.conf,b),typeof b.position=="string"&&(b.position=b.position.split(/,?\s/)),this.each(function(){c=new d(a(this),b),a(this).data("tooltip",c)});return b.api?c:this}})(jQuery);
/* Calendar AJAX */
if($('.e-tip'))
{
$(".eventful[title]").tooltip({position:"bottom center"});
}
$('.em-calendar .eventful').mouseenter(function()
{
$(this).addClass('eventful-on');
});
$('.em-calendar .eventful').mouseleave(function()
{
$(this).removeClass('eventful-on')
});
$('.em-calendar-wrapper a').unbind("click");
$('.em-calendar-wrapper a').die("click");
$('a.em-calnav, a.em-calnav').live('click', function(e)
{
e.preventDefault();
if($('em-loading') )
{
$('em-loading').remove()
}
$(this).closest('.em-calendar-wrapper').prepend('<div class="loading" id="em-loading"></div>');
var url = em_ajaxify($(this).attr('href'));
$(this).closest('.em-calendar-wrapper').load(url, function()
{
$(this).trigger('em_calendar_load');
if($.browser.msie == true && $.browser.version != "9.0")
{
$('.eventful').addClass('eventful-off')
}
$('.em-calendar .eventful').mouseenter(function()
{
$(this).addClass('eventful-on');
});
$('.em-calendar .eventful').mouseleave(function()
{
$(this).removeClass('eventful-on')
});
if($('.e-tip'))
{
$(".eventful[title]").tooltip({position:"bottom center"});
}
});
} );
