Since loading JQuery libraries from Content Delivery Network (CDN) has many advantages over hosting locally, I adopt this approach today by using script tag as:
<script src="http://ajax.microsoft.com/ajax/jquery/jquery-1.3.2.js" type="text/javascript" > </script >
I didn't expect any problem in doing that, but to my surprise, I kept getting "object expected" error on VStudio debugger. I tried with Google CDN, same error.
The error indicates that JQuery is not loaded, but what causes it? It turns out this IE setting is the reason, somehow "Active Script" is disabled in my Win2k8 Web(SharePoint 2010) Server:
Don't believe this could be a common case, but it proves CDN hosted JQuery relies on browser settings, and can fail. So the best practice is to always provide a failover to local JQuery libraries.