Created attachment 21607 [details]
Compile test case with csc: no errors
Compile test case with mcs:
Program.cs(8,35): error CS0023: The `.' operator cannot be applied to operand of type `method group'
Program.cs(9,36): error CS1061: Type `int' does not contain a definition for `Up' and no extension method `Up' of type `int' could be found. Are you missing an assembly reference?
Fixed in master