Thos error means that there is a peace of your custom code or any SharePoint element that are required an authorisation.
I suppose that you have a customized publishing site? Try to check out if there are some referenced images, documents or something similar on your page they are published.
This will be hard to track your custom code but sometimes in the code behind you need to performe some operations (access API, update, delete, insert, items etc.) which reqire you to impersonate this code. To debug your page try to select a page on which you are prompted after iis reset and try to comment peaces of your custom code before you'll find what is exactly prompting up.
Once you will find, try to see how to resolve the issue or see this post to know how to impersonate a peace of code and run this with elevated privileges.
Hope it helps,