I ran into this issue when IE8 was first released and it doesn't seem to have gotten much visibility elsewhere. IE8 Beta 1 breaks image downloads for WPF applications when the image has a web uri. From the stack trace this seems to be caused by wininet.dll not returning the internet cache folder correctly. A typical call stack for the error message might look something like this (when the uri specified is a http uri, I haven't checked FTP) A first chance exception of type 'System.ArgumentException' occurred in PresentationCore.dll System.ArgumentException: Value does not fall within the expected range. at System.Runtime.InteropServices.Marshal.ThrowExceptionForHRInternal(Int32 errorCode, IntPtr errorInfo) at MS.Win32.WinInet.get_InternetCacheFolder() at System.Windows.Media.Imaging.BitmapDownload.BeginDownload(BitmapDecoder decoder, Uri uri, RequestCachePolicy uriCachePolicy, Stream stream) at System.Windows.Media.Imaging.LateBoundBitmapDecoder..ctor (Uri baseUri, Uri uri, Stream stream, Read More...