>I am not really in control of the web site; the application resides on the customer web site. And I don't know if they set the site as "updateable" - honestly I don't even understand what it means. And I know of the need for the time for recompiling on every change. However, I have not made any changes. The only thing I am thinking is I use a lot of settings in the WEB.CONFIG to enable or disable certain parts of the main page. Maybe this is what is causing recompile.
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Yes, it is. Updating the web.config causes ASP.NET to unload the and reload the app. IIS is also set-up to automatically recycle the appdomain every 24 hours or so, and after being idle for around 15 minutes. You can adjust these settings by going into IIS, selecting Application Pools and (most likely) selecting the DefaultAppPool and right-clicking on it and selecting Properties.