Update: weird properties bug in the prototype

Okay, I sent an email to the kijaro mailing list and apparently the runtime library only has support for read-write properties. Which does indeed explain the bugs I was experiencing.
The respone:

Hi robby, thanks for testing, i will incoporate test cases based on your examples
in the test suite.
Currently properties is in a weird state between version 3 and unpublished version 4
of the spec. I've done major design changes. I have rewrittent the runtime support,
drop the writeonly properties from the spec, etc.

Currently the runtime library (java.lang.Property and helper classes)
only support read-write property, i think it explain these bugs.