ie8 Javascript Cache Issue with YUI framework

I have an application running that is using the YUI js framwork (v3.0). The user can click a button within my app which will upgrade them to the latest version of the framework (3.4). The problem is that on ie8 I'm getting some strange javascript errors. After debugging it seems that an old version (3.0) of the loader-min.js file is retrieved from the browser cache as it still being used by the YUI object when it's instantiated. So during my upgrade I create a script node, add the location to the new loader file (3.4), and then insert it into the head section. Think we're all familiar with this technique. However, when the user navigates to the next page, the file that is loaded is lost and the old version (3.0) still remains in the cache. Have verified this by using developer tools and looking at all the javascript files the app has loaded.

I've tried lots of different things to get the new version (3.4) I'm loading to override the version currently in cache, which will fix th开发者_如何学编程e javascript issues. I've tried adding a unique string to the end of the file name that is being loaded which is typically how js files can be 'versioned'. I've made sure the Etag and Cache-Control headers for the new version I'm trying to load have been set. Nothing works and I'm banging my head against the wall.

One small restriction, I have to use javascript to try and load this new version of the loader-min file. I cannot add a simple script tag to my html because of how the upgrade process works. Any thoughts, ideas, pointers as to why IE8 will not cache the version I am loading dynamically?

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Caching problems like this are normally solved by giving the new version of the script a different filename (often containing the version number) and changing the HTML that includes it to reference the new filename so that it can never be confused with the old version by a caching system.

In fact, this version system should probably be used on all external script files so when you upgrade them, you can make sure that viewers get the new version immediately and old/new versions of the scripts are never accidentally mixed by a caching system.