I am getting the same error from an assembly from a network drive that many are reporting:
Could not load the assembly file://\\C4FLibs\Coding4Fun.Phone.Controls.dll. This assembly may have been downloaded from the Web. If an assembly has been downloaded from the Web, it is flagged by Windows as being a Web file, even if it resides on the local computer. This may prevent it from being used in your project. You can change this designation by changing the file properties. Only unblock assemblies that you trust. See http://go.microsoft.com/fwlink/?LinkId=179545 for more information.
The problem is, that the files in question do not show an "Unblock" button in their properties dialog and they have no alternate data streams (checked with streams.exe). I have also tried deleting the Bin and obj directories to get rid of any copies that might have ADSs.
My question is: where else does Windows 7 store zone information other than ADSs?