typically this indicates some sort of rewriting rule (perhaps at the IIS level or even on a network device such as a proxy) - i recommend right clicking the images and seeing where they are being sourced from and trying to load them directly by that path (this removes the dotnetnuke element and will demonstrate that something is causing the path request to fail). it may also be worth checking the http statuses in a http proxy such as fiddler to see if they are 404 (missing) or a different http exception e.g. 300 level exceptions are permissions related.

---

Buy the new Professional DNN7: Open Source .NET CMS Platform book Amazon US