[Mono-dev] .exe.config supportedRuntime bug

[Quandary]

MonoDevelop (2.6 Beta) seems to generate executables with this .exe.config:

<startup><supportedRuntime version="v4.0"
sku=".NETFramework,Version=v4.0"/></startup></configuration>

When I let this run, the system complains about v4 not available (I've
compiled 2.10.1 from sources), and switches to v1, which fabulously
fails ("System.Runtime.InteropService.Marashal.Copy not implemented")...

If I delete that config entry, the program runs fine...
Shouldn't 2.10 support v4 ?