I posted an issue on SP Guidance tracker after quite some searching, but I saw several unanswered issues there so I'm trying here as well.
I think I have a very simple Proof Of Concept: a Sandbox 2010 solution, a coded web part asking for a string from a service, a feature receiver registering the service implementation at site level during activation (or install) time.
As soon as I try to get the service instance in web part CreateChildControls, I incur into this System.Runtime.Remoting.RemotingException: Failed to write to an IPC Port: The pipe is being closed. In a previous - more complex - try I was having the same exception but for a Tcp channel protocol violation: expecting preamble,and that was even during feature activation.
From the stack trace, I can see that SPUserCodeApplicationHostAppDomainRef.Execute is looking for a SPResource.GetString, and that causes reflection (?) to kick in with Activator.CreateInstance. From this stems some SPResource_SubsetProxy, which involves some proxy and then an Ipc.IpcClientTransportSink.ProcessMessage follows.
Has anyone met anything like this?
My dev box has Windows 7 64bit, SP Foundation 2010.
Of course all of this does not happen if I try with a Farm solution (and in feature activation I register mapping at site level with properties.Feature.Parent, instead of properties.UserCodeSite)