[eclipse-clp-users] Unexpected behaviour, may this be a bug ?

Hi  All,
I've recently spent a lot of time to understand why my solver failed to
instatniate the cost function during minimization, and finally I got to the
bottom of the problem which I've broken down to a simple example ( see code
below ). Can somebody please explain why this is happening ? I think that
this may be a bug in the eclipse engine.

I am using Eclipse 6.0 #90

Best regards
Luke

%------------CODE EXAMPLE BEGINNING------------%
:-module(main).
:- lib(ic).

%this does tot work as I assume it should
test1:-
    ic:(C =:= B * 2),
    B = 3,
    (9<3->true;true),

    %after the execution of the above lines C should be instatntiated to 6
but it is NOT! the constraint does not wake after the instatntiation of B to
3, can somebody explain why ? this seems to be the fault of the arithmetic
test after the unification
    writeln(ic:(C =:= B * 2)).


%if I comment out the arithmetic test everything is ok , C is 6 at the end
test2:-
    ic:(C =:= B * 2),
    B = 3,
    %(9<3->true;true),
    writeln(ic:(C =:= B * 2)).

%or if I use a constraint to instantiate B instead of unification , C is 6
at the end
test3:-
    ic:(C =:= B * 2),
    B #= 3,
    (9<3->true;true),
    writeln(ic:(C =:= B * 2)).
%------------CODE EXAMPLE END------------%