[SalesForce] Inline Editing works, but only for some fields? Can’t inline edit the Stage field.

Well, I've just tried the following code on my org with a newest Chrome and Firefox version and it reloads the entire page after save:

<apex:page standardController="Opportunity">

    <apex:detail subject="{!Opportunity.Id}" 
                 rendered="{!Opportunity.Id != null}" 
                 relatedList="True" 
                 showChatter="True" 
                 inlineEdit="true"
                 oncomplete="location.reload()"/>

</apex:page>

If you are using VisualForce Components (e.g. apex:outputPanel), their "id" value will actually be part (the end) of a longer string that defines their id in the DOM. One quick and dirty way to find the element is to use the Ends With Selector.

<apex:outputPanel id="myElement" />
<script>
    (function ($) {
        "use strict";
        console.debug($("#myElement")); // nada
        console.debug($("[id$='myElement']")); // bingo
    })(jQuery);
</script>

You can also use style class which may be more reliable/performant.

<apex:outputPanel styleClass="myElement" />
<script>
    (function ($) {
        "use strict";
        console.debug($(".myElement"));
    })(jQuery);
</script>

Or depending on the component structure you can use the $Component Global Variable. Note that this approach will not work from a Static Resource without merging in the values from the page.

<apex:outputPanel id="myElement" />
<script>
    (function ($) {
        "use strict";
        console.debug($("{!$Component.myElement}"));
    })(jQuery);
</script>