Crossfeed from Radial Decouplers
Operating System : Windows 7 Home Premium
Kerbal Version: 1.0
When a radial decoupler is attached to a fuel tank, then an additional tank is placed upon said decoupler, no crossfeed occurs when an engine fires off the stack placed upon the decoupler.
When a radial decoupler is attached to a fuel tank, then a non-tank part is placed on the decoupler, when an engine fires from the decoupler stack, fuel will flow from the central stack, acting as though the decoupler is crossfeed enabled.
Redditor tris_majestis assisted and provided an album showing the issue.