The actual message was:

This is related to previous investigation of inheriting from .NET
interface class to create WPF MVVM structure. As now I believe it has
nothing to do with interface class, but instead caused by inheriting from
.Net class overall.

please see the following code

import clr, System
class baseNA(System.Random):
    __namespace__ = "BaseNA"
    def __init__(self):
        super(baseNA,self).__init__()
#    @clr.clrmethod(System.String,[])
    def ToString(self):
        return "string"

class baseNB(baseNA):
    __namespace__ = "BaseNB"
    def __init__(self):
        super(baseNB,self).__init__()
bna = baseNA()
print bna.ToString()
print bna._Random__ToString()
bnb = baseNB()
print bnb.ToString()
print bnb._baseNA__ToString()
print bnb._Random__ToString()

This produces the following output
string
BaseNA.baseNA
BaseNB.baseNB
BaseNB.baseNB
BaseNB.baseNB

as you see, while baseNA -- the first level inherited class works fine.
ToString() overrides System.Random.ToString()

But baseNB inherited from baseNA did not inherit ToString() method from
baseNA, but rather inherited from System.Random.

This bug is still present and should be fixable by adjusting attribute lookup. @lostmsu Thoughts?