It seems that the browser, which you are using, has cached the files. If you take a look at the links generated by RadScriptManager, you will notice that there is a timestamp token in the URL, which serves for caching purposes. If the file shipped is modified, the token will be changed and the browser will request the new file. I am not sure why this is not happening on your machine, perhaps the VisualStudio integrated web-server does provide information whether a file has changed or not, therefore RadScriptManager can't modify the tamps stamp accordingly. IIS supports this for sure. I suggest that you disable caching for JS files for dev environment and leave the cache only for production, where there are no changes to the hosted files. You can disable cache using the following RadScriptManager configuration:
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