New Post: "An exception occurred during a WebClient request" only when compiling with x64 or x86

Hi,

I need to be able to compile my solution using debug/release|x86/x64.
After cloning a new workspace, if I change platform configuration to mixed platform or Any CPU it works like a charm. If I use x86 or x64 it fails only for the first time (second time it copiles without errors) with following error message:
NuGet.targets(85,9): error : An exception occurred during a WebClient request

I have just enabled nuget a few days ago on my solution so I assume I'm using the latest nuget.targets file.

Can anyone assist?

Thanks
Gil