Conflict between generic and non-generic methods overloads when return type is generic parameter

Two test cases and corresponding errors follows...

interface ITest:
def DoSomething() as string

def DoSomething[of T]() as T

class Test(ITest):
def DoSomething() as string:
pass

def DoSomething[of T]() as T:
pass

Program.boo(10,9) : Error BCE0035: 'Test.DoSomething' conflicts with inherited member 'ITest.DoSomething'.
Program.boo(7,9) : Error BCE0035: 'Test.DoSomething' conflicts with inherited member 'ITest.DoSomething`1'.

class Test2Base:
virtual def DoSomething() as string:
pass

virtual def DoSomething[of T]() as T:
pass

class Test2(Test2Base):
def DoSomething() as string:
pass

def DoSomething[of T]() as T:
pass

Program.boo(12,32) : Error BCE0072: Overridden method 'Test2Base.DoSomething' has a return type of 'string' not 'Test2.DoSomething`1.T'.